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Farmakogenetika može predvidjeti razvoj nuspojava na primjenu antipsihotika. Razlike u razvoju nuspojava na određene antipsihotike mogu se javiti, među ostalim, radi genetičkih polimorfizama. Česta nuspojava starijih antipsihotika bila je tardivna diskinezija (TD). Smatra se da TD nastaje kao posljedica vezanja antipsihotika koji djelujući kao dopaminski antagonisti izazivaju upregulaciju postsinaptičkih D2 receptora, i posljedičnu hiperaktivaciju dopamina u nigrostriatumu. Najčešće istraživane genetičke varijante koje mogu predvidjeti razvoj TD nakon primjene antipsihotike su Taq1A, -141C Ins/Del i Ser311Cys dopaminskog DRD2 receptora, Ser9Gly dopaminskog DRD3 receptora, T102C i -1438G/A serotonergičkog HTR2A receptora, Cys23Ser serotonergičkog HTR2C receptora, Val108Met kateholo-o-metiltransferaze (COMT), *1F (-163C>A) i *1C (-3860G>A) citokrom CYP1A2 enzima, te Ala9Val manganese superoxide dismutaze (MnSOD), mitohondrijalnog enzima vezanog za oksidativni stres i metabolizam1. Atipični antipsihotici često izazivaju poremećaje metabolizma glukoze i masnoća u krvi, porast tjelesne težine, pretilost, dijabetes tip II i posljedično različite kardiovaskularne bolesti. Metabolični sindrom uključuje nekoliko poremećaja: prekomjernu težinu (trbušni tip), poremećaj u regulacija masti, poremećen metabolizam glukoze i neosjetljivost na inzulin, hipertenziju, upalu koja pogoduje razvoju ateroskleroze, povišene vrijednosti nekih enzima jetre i mokraćne kiseline. Atipični antipsihotici pokazuju relativno slab afinitet prema dopaminskim DRD2, ali imaju afinitet prema DRD3 i DRD4 i monoaminskim (5-HT2A, 5-HT2C i histaminski H1) receptorima. Porast tjelesne težine izazvan antipsihoticima se povezuje s primjenom lijekova s visokim afinitetom za serotonergičke 5-HT2C, te H1 receptore, leptin, dok se dijabetes može javiti nakon primjene lijekova koji djeluju kao antagonisti perifernih M3 muskarinskih i središnjih 5-HT2C receptora1, 2, 3. Antipsihoticima izazvan porast tjelesne težine povezan je s antagonizmom H1, adrenergičkih alfa1A, 5-HT2C i 5-HT6 receptora. Dopaminski sustav ima ulogu u porastu tjelesne težine izazvane antipsihoticima, jer kontrolira unos hrane, potrošnju energije, metabolizma glukoze i lipida, krvnog tlaka i oslobađanja inzulina. Smanjena dopaminska neurotransmisija se povezuje s razvojem pretilosti i otpornosti na inzulin, a antagonizam dopaminskih D2 receptora može povećati učinke posredovane putem 5-HT2C receptora na unos hrane ili utjecati na metabolizam lipida i glukoze putem disinhibicije oslobađanja prolaktina. Dopaminski D2 receptori su slabije eksprimirani u mozgu pretilih ljudi, a aktivacija ovih receptora poboljšava metabolizam glukoze, smanjuje krvni tlak i stimulira potrošnju energije kod pretilih pojedinaca. Osim toga, dugoročna terapija D2 agonistima (bromokriptin) poboljšava metaboličku kontrolu kod pretilih ljudi s dijabetesom tipa II. Farmakogenetska istraživanja uputila su na povezanost C-759T (rs3813929) polimorfizma 5-HT2C receptora i porasta tjelesne težine izazvanog antipsihoticima, te C825T polimorfizma gena koji kodira b3 podjedinicu G proteina (GNB3) s hipertenzijom, pretilošću i povećanom tjelesnom težinom. Nadalje, pokazana je povezanost genetičkih varijanti (rs3766522 i rs10789038) gena koji kodira alfa katalitičke (PRKAA1, PRAKAA2) i beta regulatorne (PRKAB1, PRKAB2) podjedinice AMP-aktivirane protein kinase 3. Dakle, farmakogenetika je sastavni dio personalizirane medicine te pomaže u identifikaciji povećanog rizika za razvoj nuspojava lijekova kod osoba koje nose određene varijante gena, te u odabiru najboljeg i odgovarajućeg liječenja i razvoju novih lijekova koji su sigurni, bez nuspojava, ciljani i individualizirani. Literatura 1. Zhang J-P, Malhotra AK. Pharmacogenetics and antipsychotics: therapeutic efficacy and side effects prediction. Expert Opin Drug Metab Toxicol 2011 ; 7:9-37 2. Reynolds GP, Kirk SL. Metabolic side effects of antipsychotic drug treatment – pharmacological mechanisms. Pharmacol Therapeut 2010 ; 125:169–179. 3. Souza RP, Tiwari AK, Chowdhury NI, Ceddia RB, Lieberman JA, Meltzer HY, Kennedy JL, Muller DJ. Association study between variants of AMP-activated protein kinase catalytic and regulatory subunit genes with antipsychotic-induced weight gain. J Psych Res 2012: doi:10.1016/j.jpsychires.2012.01.010

Patients with psychotic disorders frequently develop side effects after antipsychotic treatment. Pharmacogenetic studies reported significant associations, but also the lack of associations, between the genetic variants of catechol-o-methyltransferase (COMT Val158Met)and brain-derived neurotraphic factor (BDNF Val66Met) and particular antipsychotic-induced side effects. Since atypical antipsychotics frequently induce metabolic side effects, the aim of the study was to evaluate the association between antipsychotic-induced side effects and genetic variants of COMT Val158Met and BDNF Val66Met. The study included 128 male and female patients with schizophrenia (diagnosed using Structured clinical interview based on DSM-IV criteria) who were treated for 6 months with atypical antipsychotics (clozapine 25-500 mg/d, risperidone 1-10 mg/d, olanzapine 5-20 mg/d, quetiapine 50-800 mg/d). Patients were subdivided into non-risk and risk groups based on: body mass index (BMI) (higher than 25), glucose (higher than 6.1 mmol/L), high density lipoprotein (HDL) cholesterol (for women lower than 1.3mmol/L ; for men lower than 1.0 mmol/L), waist circumference (for women higher than 88 cm ; for men higher than 102 cm), blood pressure (higher than 130/85 mm Hg), triglycerides (higher than 1.7 mmol/L), and presence/absence of the metabolic syndrome. COMT Val158Met (rs4680) and BDNF Val66Met (rs6265) genotypes were determined using the TaqMan SNP Genotyping Assay. Results were evaluated using χ2 test and one-way ANOVA. In all patients waist circumference (F=3.447 ; P=0.035) and triglyceride concentrations (F=4.289 ; P=0.021) were significantly lower in carriers of COMT Met/Met genotype than in other COMT genotypes. When patients were subdivided according to gender, the frequency of BDNF Val66Met genotypes differed significantly (χ2=9.740 ; P=0.0076) between male risk and non-risk groups according to glucose concentration. Male carriers of BDNF Met/Met genotype had significantly (F=5.211 ; P=0.010) lower plasma glucose concentration than carriers of BDNF Met/Val or Val/Val genotypes. In female patients, the distribution of COMT Val158Met genotypes was significantly different between risk and non-risk groups according to triglyceride concentration (χ2=7.413 ; P=0.0246). ANOVA revealed that female carriers of COMT Met/Met genotype had significantly lower waist circumference (F=5.077 ; P=0.008) and BMI (F=3.163 ; P=0.047) than female carriers of COMT Met/Val or Val/Val genotypes. Other side effects were not significantly (P > 0.05) associated with COMT Val158Met or BDNF Val66Met genotypes. In conclusion, BDNF Val66Met was significantly associated with the risk of higher glucose concentration in male patients, while COMT Val158Met was significantly associated with the risk of increased triglyceride concentration, waist circumference and BMI in female patients. Both BDNF and COMT Met/Met genotype carriers had significantly lower values than carriers of other genotypes. This preliminary pharmacogenetic study revealed sex-related differences and significant association between atypical antipsychotic-induced side effects and COMT Val158Met or BDNF Val66Met. Therefore, further studies should enlarge the groups to elucidate whether COMT Val158Met or BDNF Val66Met might be used as markers of metabolic side effects, with aim to improve treatment response and compliance and to reduce health risk.

Patients with alcohol dependence frequently experience sleep disturbances and insomnia. These problems manifest as difficulties in falling or staying asleep, waking up frequently at night or too early in the morning, feelings of fatigue, and lack of refreshment after the broken or unsatisfying sleep. Therefore, patients with alcohol dependence frequently use hypnotics and benzodiazepines as self-medicatation to alleviate sleep disturbances. The aim of the study was to examine sex differences in the use of hypnotics and benzodiazepines in patients with alcohol dependence with sleep disturbances. The study was conducted at the Centre for Alcoholism and Other Addictions, University Psychiatric Hospital Vrapce, Zagreb. Patients with alcohol dependence were diagnosed with Structured Clinical Interview for DSM-IV, and were subdivided into 51 male (49.5 ±10.5 years, range 26-72) and 51 female (52.0 ±10.2 years, range 29-69) participants. Drugs used were zolpidem, nitrazepam, midazolam, flurazepam, diazepam, oxazepam, alprazolam, lorazepam, or bromazepam, and patients were evaluated 5-10 days after admission. Insomnia was evaluated using items 4 (early insomnia), 5 (middle insomnia) and 6 (late insomnia) from the Hamilton Depression Rating Scale /HDRS/. All participants were additionally evaluated using Structured questionnaire for anamnesis data and Structured questionnaire for the history of hypnotic and benzodiazepine use. The results were evaluated with χ2 test, one-way ANOVA or Student’s t-test. When male alcoholic subjects were compared to female subjects, they had similar HDRS scores on early (1.41±0.57 vs. 1.51±0.51) middle (1.29±0.73 vs. 1.18±0.80) or late (0.59±0.85 vs. 0.76±0.95) insomnia, respectively. Male and female patients with alcohol dependence with insomnia differed significantly (χ2 = 18.191, df=9 ; p=0.033) in the first use of hypnotics or benzodiazepines, since female patients more frequently used oxazepam as a first medication for treating insomnia. Female alcoholic patients with insomnia used significantly higher number of medications than male patients (3.98±1.75 vs. 3.20±1.69), and this sex difference was significant (t=2.306 ; df=100 ; P=0.023). There were no sex related differences in the occurrence of the first problems with sleep (t=0.208 ; df=100 ; P=0.835), most frequently used medication for sleep disturbances (χ2 = 3.950, df=6 ; P=0.683), use of the higher dose than prescribed (χ2 = 1.231, df=1 ; P=0.267), use of medication more than one month (χ2 = 0.000, df=1 ; P=1.000), use of medication without prescription (χ2 = 0.068, df=1 ; P=0.795) or information about the side effects (χ2 = 0.055, df=1 ; P=0.815). These results show that alcoholic patients frequently experience insomnia and use hypnotics or various benzodiazepines as a self-medication or after prescription. Besides the symptoms of insomnia, benzodiazepines might also alleviate the symptoms of alcohol withdrawal. The use of hypnotics or benzodiazepines, especially oxazepam, occurred earlier in female that in male alcoholic patients with insomnia, and female patients used more frequently the combination of up to 4 drugs daily. In conclusion, these preliminary data indicate that hypnotics and benzodiazepines should be closely monitored, especially in female alcoholics with insomnia, to avoid self medication and addiction.

Rationale Ziprasidone is an atypical antipsychotic, with the unique multireceptor-binding profile. If affects multiple serotonergic (5-HT) receptors, inhibits 5-HT transporter (5-HTT) and inhibits synaptic 5-HT reuptake. These effects might be responsible for the antidepressant effect of ziprasidone. Objectives Since there is a lack of in vivo data on the effects of ziprasidone on 5-HT concentration in humans, the aim of the study was to investigate the effect of ziprasidone treatment on platelet 5-HT concentration in patients with schizophrenia or schizoaffective disorders. Methods In and open-label study, the effect of ziprasidone (average dose of 109 mg/day) on platelet 5-HT concentration (determined fluorimetrically) was evaluated at baseline and after 7 and 28 days of treatment in 21 male and female patients with schizophrenia or schizoaffective disorders. Results Ziprasidone treatment for 7 or 28 days did not significantly change baseline platelet 5-HT concentration in male and female schizophrenic patients. Platelet 5-HT concentration was not correlated with gender, age and smoking status of patients. Conclusions There was a lack of effect of ziprasidone treatment on platelet 5-HT concentration in male and female schizophrenic patients. Although the clinical effects of ziprasidone were evident after 28 days of treatment, and ziprasidone has the highest potency among atypical antipsychotics to block 5-HTT, our data did not confirm the hypothesis that ziprasidone treatment decreases platelet 5-HT concentration, at least not in the doses used in our study.

Background Gamma-aminobutyric acid-A (GABA-A) receptors, the major inhibitory neurotransmitter receptors in the brain are implicated in the acute and chronic effects of alcohol, including tolerance, dependence and withdrawal. Various polymorphisms in the gene encoding the GABA-A receptor alpha2 subunit (GABRA2) have been associated with alcoholism and with antisocial behavior in different populations of European ancestry. As early onset of alcoholism often reflects greater severity, including a higher risk for recurrence, comorbid antisocial personality disorder and conduct disorder, Cloninger’s classification distinguishes type II alcoholism with an early onset, elevated levels of antisocial behavior and delinquency, from the type I alcoholism with a late onset, neurotic symptoms and minimal criminality. Materials and methods Genotyping of GABRA2 polymorphisms (rs567926, rs279858 and rs9291283) was performed in samples of 355 alcoholic patients of Croatian origin (280 males and 75 females) using TaqMan Real-Time allelic discrimination technique after extraction of DNA from the whole blood. The results of allelic and haplotypic analysis were compared between alcohol-dependent subjects with a combination of early onset of alcohol abuse and presence of aggressive behavior corresponding to type II alcoholism subgroup, and individuals with the late onset of alcohol abuse and without aggression corresponding to type I alcoholism subgroup, according to Cloninger. Results Cloninger’s Type I and Type II alcohol- dependent patients did not differ significantly in the frequency of the genotypes and alleles for rs567926, rs279858 or rs9291283. However, the G-T- G haplotype was more often present in the alcohol- dependent subjects with early onset of alcohol abuse and aggressive behavior, corresponding to the Cloninger type II alcoholism subgroup (χ2 = 6.102, p = 0.013). Conclusions Our results revealed a haplotypic association between the GABRA2 gene and a more severe form of alcoholism, characterized by the early onset of alcohol abuse and presence of aggressive behavior. These findings support an important role of GABA-A receptors in the susceptibility to alcoholism and highlight them as potential targets for novel therapeutics in the treatment of alcohol dependence.

Rationale: Although antipsychotic drugs are prescribed for the treatment of schizophrenia and psychotic disorders, some of these drugs are also reported to possess antidepressant properties. Therefore, they are more frequently used either as a monotherapy or as an addition to antidepressant medication treatment in depression. Objectives: The data on the effects of antipsychotic drugs on serotonin (5-hydroxytryptamine, 5-HT) transporter (5-HTT) in vivo when given to patients in therapeutic doses are still scarce. Methods: Patients with schizophrenia or schizoaffective disorders in both male and female patients, were treated with antipsychotic drugs: 25 patients received olanzapine (12.8 ± 2.8 mg/day), 14 patients were treated with typical antipsychotic, fluphenazine N=14 (10.5 ± 2.5 mg/day) and for comparison, 21 patients were treated with ziprasidone (109.0 ± 27.1 mg/day). Platelet 5-HT concentration was determined fluorimetrically and evaluated at baseline and after 28 days in 65 healthy control subjects and in 60 patients. Results: Platelet 5-HT concentration did not differ significantly [F(3, 246)=0.597 ; p=0.677] between medicationfree healthy control subjects sampled at baseline and after 28 days compared to schizophrenic patients sampled before and 28 days after antipsychotics. Tukey’s multiple comparison test revealed that treatment with fluphenazine (p=0.853), olanzapine (p=0.117), or ziprasidone (p=1.000) did not significantly alter platelet 5-HT concentration after 28 days of treatment compared to their baseline values, i.e. values before treatment. Conclusions: Although all antipsychotics used in the study possess some antidepressant effects that are assumed to be related to their serotonergic properties, and have been reported to have in vitro binding affinity for human 5-HTT, the present study failed to detect significant in vivo effects of typical (fluphenazine) or atypical (olanzapine, ziprasidone) antipsychotics on platelet 5-HT concentration in schizophrenic patients.

Sindrom ovisnosti o alkoholu je skup fenomena gdje konzumiranje alkohola za pojedinca predstavlja prioritet u odnosu na ostala ponašanja. Dopaminergički sustav ima važnu ulogu u mehanizmima nagrade u mozgu te tako i kod razvoja ovisnosti. U osnovi alkoholizma genetika ima udio 40-60%. U genu dopaminskog receptora D4 pronađen je polimorfizam s varijabilnim brojem uzastopnih ponavljanja. Najčešće su varijante sa 4 i 7 ponavljanja. Polimorfizam može utjecati na vezanje dopamina na receptor, vezu sa sekundarnim glasnikom te na prijenos signala. Poremećaj pažnje s hiperativnošću (ADHD) je multifaktorijalan i izrazito nasljedan razvojni poremećaj ponašanja koji se javlja kod 3-7% djece školskog uzrasta. Istraživanja provedena na posvojenoj djeci i blizancima pokazale su da je ADHD izrazito nasljedan neuropsihijatrijski poremećaj (76%). Dopaminergička teorija o razvoju ADHD-a temelji se na mnogim farmakološkim i mozgovnim slikovnim studijama te životinjskim modelima. Aktivnost katehol-O-metiltransferaze regulirana je funkcionalnim polimorfizmom Val158/108Met, kojeg karakterizira zamjena aminokiseline valin s aminokiselinom metionin. Ovaj polimorfizam smatra se jednim od rizičnih faktora za razvoj ADHD-a. Alzheimerova bolest je neurodegenerativna bolest koja se javlja u starijoj dobi. Nastanak bolesti je posljedica interakcije gentičkih čimbenika i okoline. Poznati su neki rizični čimbenici u nastanku bolesti, no sam mehanizam nastanka je nepoznat. Nekoliko teorija pokušava objasniti taj mehanizam od kojih je jedna, teorija moždane upale. Osim promjena koje nastaju upalnim procesima dolazi i do promjena u neurotransmisiji. Važno je rasvjetliti mehanizme interakcije medijatora upale i neurotransmiterskih sustava u mozgu, jer npr. noradrenalinski sustav pokazuje mogući kompenzacijski učinak, a mogao bi biti pod kontrolom medijatora upale.

gamma-aminobutyric acidA (GABAA) receptors, the major fast inhibitory neurotransmitter receptors in the brain, are implicated in the acute and chronic effects of alcohol including tolerance, dependence and withdrawal. Recent studies have suggested a linkage of alcohol dependence to the gene encoding GABAA receptor 2 subunit (GABRA2), on chromosome 4p. Therefore we examined the association of alcohol dependence to rs9291283 (hCV8262290) polymorphism, located in the intron 3 of GABRA2 gene, that has been previously reported to be implicated in alcoholism. This study enrolled 379 (303 male and 76 female) alcohol- dependent (diagnosis of alcoholism was made according to DSM-IV criteria) and 226 (198 male and 28 female) healthy subjects of the Croatian origin. Alcohol-dependent patients were further subdivided according to the early/late onset of alcohol drinking, as well as to the presence/absence of aggressive behavior. Genotyping was performed by using TaqMan Real-Time allelic discrimination technique after extraction of DNA from the whole blood with a salting out procedure. There were no significant differences in the distribution of genotypes or in the frequency of different allele carriers for tested polymorphism between alcohol-dependent and control individuals, as well as between different subsets of alcoholics. The results have not provided supporting evidence for the potential involvement of the rs9291283 (hCV8262290) GABRA2 polymorphism in the alcohol dependence. However, since these are preliminary results, further studies with enlarged groups should be conducted in order to find a possible association of investigated polymorphism and alcoholism in Croatian population.

Posttraumatic Stress Disorder (PTSD) is assumed to represent a marker of stress vulnerability rather than a reaction after exposure to a trauma. The underlying biology of PTSD consists of the pre-traumatic biological and physiological risk factors that affect the ability to cope with the traumatic event. Diagnoses involving pain are extremely common among war veterans. The prevalence of chronic pain occurs more frequently in subjects with PTSD (25-80%) than in control subjects, while chronic pain patients have more frequent PTSD than other groups. It is proposed that PTSD mediates chronic pain symptoms. The biological substrates of vulnerability to PTSD and pain include central neurotransmitters, neurotrophic factors, and neuroendocrine systems, while physiological factors include those related to attention, hyperarousal, avoidance, cognition, and anxiety. The severity of PTSD has been found to be correlated with the severity of chronic pain. The neurobiological mechanisms underlying altered pain perception in combat exposed veterans with PTSD are still unclear. Therefore, the aim of this preliminary study was to assess peripheral biomarkers (platelet serotonin [5-HT] concentration, platelet monoamine oxidase type B [MAO-B] activity) and to determine genetic polymorphisms of MAO-B, dopamine-beta-hydroxylase (DBH), catechol-o-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF), serotonin transporter (5-HTT), and serotonin 5HT2A receptor, in male Croatian war veterans with current and chronic combat-related PTSD subdivided into those with or without pain syndrome. The objectives were to elucidate the distribution of the genotypes or alleles for MAO-B intron 13, -1021C/T DBH, Val158/108Met COMT, Val66Met BDNF, 102T/C 5HT2A polymorphisms and 5-HTT gene-linked polymorphic region (5-HTTLPR), and to explore the relation between these variants and pain syndrome in combat-related PTSD. The hypothesis of this study was that these biomarkers would differ between veterans with or without pain syndrome. Since it has been shown that early treatment of pain would prevent the development of chronic pain syndrome, this study aimed to find biomarkers that would provide earlier treatment of pain syndrome, in order to reduce consequences of the pain-related conditions in veterans with PTSD. Participants (N=142) included in the study were unrelated, medication-free Caucasian male war veterans with combat-related PTSD. Veterans had current and chronic PTSD, diagnosed using the Structured Clinical Interview (SCID) based on DSM-IV Disorders. Veterans were categorized according to the presence of pain syndrome into those with or without pain syndrome. The biological and genetic markers were determined from the blood samples using biochemical and genetic analyses. The results, expressed as means ± standard deviations, were evaluated using one-way analysis of variance, and differences in the genotype and allele frequencies were evaluated using a 2 test. Although altered platelet 5-HT concentration was associated with particular symptoms in PTSD, platelet 5-HT concentration was not significantly different between veterans with or without pain syndrome. These results suggest that platelet 5-HT is not a biomarker of the pain syndrome in PTSD. Platelet MAO-B activity, controlled for the smoking status, did not differ significantly between veterans with or without pain syndrome. These data did not confirm the hypothesis that platelet MAO-B might be used as a peripheral marker of the pain syndrome in PTSD. The frequencies of the MAO-B intron 13, DBH-1021C/T, COMT Val158/108Met, BDNF Val66Met, 102T/C 5HT2A, 5HTTLPR variants did not differ significantly between groups of veterans with PTSD with or without pain syndrome, presumably due to the small number of included veterans. In conclusion, our preliminary findings suggest that although combat experience affects the circuits mediating stress response, as well as neural circuitry underlying pain processing, the selected biomarkers, which have been shown to be associated with particular psychopathological symptoms or altered behaviours in PTSD, were similar between groups of veterans with PTSD with or without pain syndrome. These data suggest that further additional studies with larger groups are warranted to shed further light on these associations.

Shizofrenija je kompliciran dijagnostički entitet sa značajnim razlikama u kliničkoj prezentaciji bolesti, odgovoru na lijekove i tijeku bolesti. Neurobiološka podloga uključuje neurokemijske promjene i to one neurotransmitorskih sustava, prvenstveno dopamina. Dolazi do promjene subkortikalne dopaminergičke aktivnosti za vrijeme akutne psihotičke faze bolesti. Povećana aktivnost dopamina temeljena na nalazima da su svi efikasni antipsihotici blokatori dopaminergičkih receptora te da je njihova efikasnost povezana s afinitetom vezanja za dopaminergičke receptore tipa 2 (DRD2) u mozgu, te da primjena lijekova koji povećavaju dopaminergičku aktivnost, izaziva egzacerbaciju psihotičkih simptoma u nekih osoba sa shizofrenijom. Shizofrenija je nasljedna u oko 80% slučajeva. To je poligenska bolest i geni u kombinaciji sa čimbenicima iz okoline povećavaju rizik razvoja bolesti. Od najčešćih rizičnih gena koji pojačavaju rizik od nastanka shizofrenije spominju se geni vezani za dopaminegički sustav, pa tako i COMT (katehol-o-metil-transferaza). To je enzim koji inaktivira dopamin, noradrenalin i adrenalin koji su odgovorni za regulaciju pažnje, raspoloženja i odgovora na stres. Smatra se da je COMT rizični čimbenik za ADHD, shizofreniju, ovisnosti, bipolarni poremećaj, i suicidalno ponašanje. Aktivnost COMT enzima regulirana je funkcionalnim Val158/108Met (rs4680) polimorfizmom, kojeg karakterizira zamjena aminokiseline Valin (Val) s aminokiselinom Metionin (Met), (rezultat zamjene G→A u eksonu 4 gena COMT). Populacija shizofrenih bolesnika je pod većim rizikom za razvoj debljine, diabetesa tipa 2, dislipidemije, hipertenzije odnosno metaboličkog sindroma u odnosu na opću populaciju. Ciljevi ovog preliminarnog istraživanja bili su 1) istražiti frekvenciju pojavljivanja COMT polimorfizma u muških i ženskih shizofrenih bolesnika bijele rase hrvatskog porijekla i usporediti tu frekvenciju s onom u zdravih ispitanika, i 2) istražiti potencijalnu ulogu COMT polimorfizma u razvoju metaboličkog sindroma u shizofrenih bolesnika. U studiji su bili uključeni shizofreni bolesnici, podijeljeni na one sa ili bez metaboličkog sindroma. Metabolički sindrom bio je definiranom povećanim vrijednostima za 4 karakteristična simptoma: opseg struka, razina glukoze natašte, serumski HDL kolesterol i indeks tjelesne mase. Kod muških pacijenata sa shizofrenijom uočena je značajno veća frekvencija pojavljivanja COMT AA (Met/Met) genotipa te A (Met) alela nego kod zdravih kontrola. Međutim, kod muških pacijenata s metaboličkim sindromom uočena je značajno veća frekvencija pojavljivanja COMT GG (Val/Val) genotipa te G (Val) alela nego kod pacijenata bez metaboličkog sindroma. Ti nalazi upućuje na veću aktivnost COMT enzima u metaboličkom sindromu koja onda rezultira i manjom razinom dopamina kod ovih pacijenata te posljedično i slabijom dopaminskom neurotransmisijom. Kod žena nisu primjećene nikakve razlike u frekvenciji pojavljivanja COMT varijanti između pacijentica sa i bez shizofrenije i/ili metaboličkog sindroma. Ti preliminarni podaci upućuju na zaključak da se istraživanja trebaju nastaviti na povećanim skupinama bolesnika koje će biti podijeljene prema propisivanim lijekovima.

High rates of suicide among adolescents are a growing concern worldwide, while 8% of adolescents show high suicidal risk in Croatia. There are different psychiatric, psychological, environmental, biological and genetic factors for suicidal behavior that can lead to completed suicide. Aggression and agitation present risk factors for suicide. Gene for the enzyme catechol-o-methyl-transferase (COMT), that degrades dopamine, is frequently studied candidate gene for suicide risk. A functional polymorphism COMT Val108/158Met, consists of G to A transition, i.e. substitution of valine (Val) with methionine (Met). The Val/Val genotype has a 3-4 times higher COMT activity than the Met/Met genotype. This polymorphism was associated with suicidal behavior in adults. The hypothesis of this study was that COMT Val108/158Met polymorphism will be significantly associated with suicidal behavior and/or aggression in adolescents. The study included 187 female and 141 male adolescents (15.2 ± 2.4 years, range 7-19). The psychiatric diagnoses, suicidal behavior and aggression were established according to the SCID and DSM- IV criteria, and the Overt Aggression Symptom Checklist. DNA was isolated from the blood samples taken during regular laboratory check- ups. Genotyping was carried out on the ABI Prism 7000 Sequencing Detection System apparatus (ABI, Foster City, USA) with Taqman- based allele-specific PCR, according to the procedure described by Applied Biosystems (ABI, Foster City, USA). Statistical evaluation of the data was done using the Chi-square test, with p

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a complex and multifactorial disorder characterized by three behavioral symptoms: impulsivity, hyperactivity and/or inattention. These symptoms often lead to accidents and affect interpersonal relationships by causing inappropriate behavior. Symptoms of inattention are more persistant than symptoms of hyperactivity/impulsivity. Inattention is often associated with skill deficits and academic and social dysfunction in adults with diagnosed ADHD in childhood. Altough the neurobiological basis of ADHD implies dysfunction of dopaminergic, noradrenergic and serotonergic systems, the most investigated neurotransmitter system in ADHD is the dopaminergic system. Dopamine (DA) modulates behavior and cognition via fronto-striato-cerebellar circuits and consequently pharmacotherapy of ADHD targets these systems. Monoamine oxidase (MAO) is an enzyme that catalyzes oxidative deamination of dietary amines and monoamine neurotransmitters such as dopamine. Platelet MAO (MAO-B), which is also expressed in serotonergic neurons and astrocytes, has been proposed to represent a peripheral marker for a variety of personality traits including ADHD. There are five different dopamine receptors divided in two groups (D1 like and D2 like dopamine receptors). Many studies found a significant role of the dopamine D4 receptor (DRD4) gene, specifically the 7-repeat allele of the exon III variable number of tandem repeats (VNTR), in the etiology of ADHD. Aim of our study was to determine platelet MAO-B activity and the distribution of the DRD4 genotypes in children with ADHD and in healthy children. Materials and Methods: Platelet MAO-B activity was evalueted with a spectrofluorimetric method in 87 boys and 13 girls with ADHD (DSM-IV criteria) and in 329 healthy control children (152 boys and 177 girls). DRD4 genotype was determinated using polymerase chain reaction (PCR) and agarose gel electrophoresis in 94 children with ADHD. Results: Platelet MAO-B activity was significantly lower in children with ADHD, or in children with subtypes of ADHD, compared to control children. The DRD4 variants did not differ significantly among children with ADHD. No significant association was found between platelet MAO-B activity and gender and/or particular DRD4 genotype. Conclusions: Reduced platelet MAO-B activity in children with ADHD suggests that platelet MAO-B migh be used as a biomarker of disrupted behavior in psychopathological conditions such as ADHD. Platelet MAO-B activity was not associated with DRD4 genotype. Further study on larger sample of patients is needed to clarify the role of MAO-B and DRD4 in ADHD.

Attention-deficit/hyperactivity disorder (ADHD) is a multifactorial, highly heritable developmental disorder which affects 3-7% of school-aged children. ADHD is characterized by behavioral symptoms of impulsivity, hyperactivity and/or inattention. Individuals with diagnosed ADHD meet the DSM-IV diagnostic criteria for one of the three main subtypes of ADHD: combined type, predominately inattentive type or predominately hyperactive-impulsive type. The role of solute carrier family 9 (sodium/hydrogen exchanger) isoform 9 (SLC9A9) in ADHD was recently suggested in a genome-wide association study for ADHD. The SLC9A9 protein, which is localized on the late recycling endosomes, may play an important role in maintaining cation homeostasis which is important for normal functioning of neuronal cells. Materials and Methods: We aimed to analyze two single nucleotide polymorphisms (SNPs), rs9289659 and rs4839604, near the 3’-untraslated region of the SLC9A9 gene. The study included 93 medication free children with ADHD, with an average age of 9 years (ranging from 4 to 20 years), recruited sequentially from the Polyclinic Kocijan/Hercigonja, Zagreb. ADHD was diagnosed with psychiatric interview, according to the DSM-IV criteria, separate interviews with the children and their parents, psychological interview, psychological tests, physical examination and the short version of the Conners’ Rating Scale for Parents. Children without psychiatric diagnoses and free of medication served as control group (N = 131), with an average age of 13 years (ranging from 6 to 18 years). SNPs were genotyped with the ABI Prism 7000 Sequencing Detection System apparatus. The association of these two polymorphisms with ADHD features was evaluated using the χ2-test in Sigma Stat 3.5. Results: We found an association between rs9289659 genotypes and the symptoms of inattention in children diagnosed with ADHD. An association with ADHD features was also found for rs4839604 genotypes, particularly for predominately inattentive type and combined type. A significant difference was found in rs4839604 allele frequencies between healthy control subjects and patients with predominately inattentive type. There were no differences in genotype frequencies between male and female patients and male and female control subjects. Conclusions: The SLC9A9 protein may be linked to the symptom-based phenotypes observed in ADHD patients. Our study suggests an association of rs9289659 with DSM-IV inattentive symptom subscales and in case of rs4839604 with inattentive and total symptom subscales. These data should be further investigated on a larger sample to confirm or refute these findings.

Insomnia is an integral part of sleep disorders, frequently comorbid with different psychiatric disorders. Insomnia is a very common, characterized by difficulties in falling or staying asleep and non-restorative sleep. It is associated with daytime fatigue, reduced physical and social performances, and lower quality of life. It affects a large part of healthy population and patients with schizophrenia, depression, alcoholism, posttraumatic stress disorder (PTSD), Alzheimer's disease, Parkinson's disease. The neurobiological basis of insomnia includes the alterations in different neurotransmitter pathways, immune signaling molecules and hormones. Serotonin (5-hydroxytryptamine, 5-HT) controls sleep, wakefulness, arousal states, vigilance behaviors, synchronization of the biological clock and circadian rhythmicity. In addition, altered function of 5-HT is implicated in depression, alcoholism and PTSD, and these disturbances are frequently associated with insomnia. The main regulator of the 5-HT activity is a 5-HT transporter (5-HTT), identical in neurons and platelets, encoded by the same (SLC6A4) gene. A 5-HTT gene-linked polymorphic region (5-HTTLPR) in SLC6A4 is a functional polymorphism associated to vulnerability or resiliency to develop psychiatric disorders and addictions. Platelets might be used as a limited peripheral marker of the central 5-HT synaptosomes since they similarly store, release and metabolize 5-HT. Platelet markers (monoamine oxidase (MAO-B) activity and platelet 5-HT concentration) are altered in particular symptoms, traits, and behaviors in psychiatric disorders, while platelet 5-HT and 5-HTTLPR variants were reported to be changed in subjects with desynchronized circadian rhythm. Aim of this study was to evaluate these biomarkers in patients with alcoholism, depression and PTSD (diagnosed using Structured Clinical Interview based on DSM-IV criteria), subdivided into those with or without insomnia (evaluated using psychiatric interview, Hamilton Rating Scale for Depression and Anxiety, and Clinician Administered PTSD Scale). Biomarkers investigated were platelet 5-HT concentration, platelet MAO activity and 5-HTTLPR variants. Our results showed that platelet 5-HT concentration was significantly lower in male alcoholic patients with middle insomnia compared to male alcoholic patients without middle insomnia, and in male veterans with PTSD with insomnia or with flashbacks than in male veterans without insomnia or flashbacks. Platelet MAO activity was not affected by insomnia in alcoholism, PTSD and depression. The frequency of the 5HTTLPR genotypes (LL, LS or SS) or alleles (L or S) differed significantly in male veterans with PTSD subdivided into those with or without early insomnia. The data confirm that there is a bidirectional relationship between PTSD, depression, alcoholism and insomnia. Altered 5-HT biomarkers associated with insomnia stress the need to reveal the neurobiological mechanisms of insomnia and to develop targeted interventions for both insomnia, as well as PTSD, depression, and alcoholism.

Introduction: Behavioral and emotional disorders are highly prevalent and heterogeneous common disorders in children and adolescents that include attention- deficit/hyperactivity disorder (ADHD), adjustment disorders, anxiety disorders, obsessive/compulsive disorder (OCD), posttraumatic stress disorder, conduct disorder, oppositional defiant disorder, depression and others. These disorders are frequently associated with the negative outcomes in adulthood, substance abuse and dependence, early pregnancy, persistent health problems, increased aggression, impulsivity, hyperactivity, inattention, obsessions, compulsions, anxiety, suicidality, delinquency, and criminality. These disorders are multifactorial and heterogeneous, with a complex etiology and strong genetic component. No single deficit is sufficient to explain all clinical cases of these disorders. Various child-specific, environmental, demographic, psychosocial, psychiatric, cognitive, developmental and genetic factors, with the stress exposure or adverse early life experiences, and a complicated interplay of these factors, contribute to the development and maintenance of these disorders and antisocial, violent and suicidal behaviors. The neurobiological basis of these disorders is not clear, but it is assumed to involve particular gene mutations and altered functions of the main neurotransmitter (dopamine, norepinephrine, serotonin /5-HT/) and neuroendocrine (hypothalamic-pituitary-adrenal axis) systems. Materials and Methods: Platelet markers, monoamine oxidase (MAO-B) and 5-HT, and polymorphisms of the genes for catechol-o- methyl-transferase (COMT) and brain derived neurotrophic factor (BDNF) were determined in male and female children with depression, OCD, ADHD, and phobias. Children were further subdivided according to the gender and suicidal behavior. Clinical diagnoses and suicidal behavior were assessed according to the DSM-IV criteria, different clinical scales and the psychiatric interview. Results: Significant differences were found in platelet 5-HT concentration between healthy boys and girls, but not among suicidal and non-suicidal children. Significant differences in the frequency of the Val66Met BDNF genotypes between suicidal, non-suicidal and healthy groups were detected. The distribution of the Val158/108Met COMT variants, and platelet MAO-B activity, did not differ significantly between the studied groups. Discussion: Our results did not support the hypothesis that reduced platelet 5-HT concentration or lower platelet MAO-B activity or Val158/108Met COMT variants present the risk factors for suicidal behavior in children. The significant contribution of the Met/Val genotype of the Val66Met BDNF to the observed significance suggested that Val66Met BDNF might present a risk factor for suicidal behavior. This result should be confirmed on the larger sample. Since the clinical features of behavioral and emotional disorders are heterogeneous and complex, further research of the risk factors for suicidal behavior is important to identify and properly treat children and adolescents prone to suicidal behavior, in order to prevent suicidal behavior, suicidal attempts and completed suicides.

Shizofrenija je ozbiljna psihijatrijska kronična bolest, koja pogađa oko 1% svjetske populacije, a u ovom tekstu se najvećim dijelom obrađuje njezina neurobiološka osnova. Raznovrsni simptomi shizofrenije se obično javljaju u ranoj odrasloj dobi i dovode do ozbiljnih poremećaja na društvenom i poslovnom polju. Simptomi shizofrenije uobičajeno se dijele na pozitivne, negativne, kognitivne (spoznajne) i afektivne (simptome promijenjenog raspoloženja). Bolest karakterizira tipičan uzorak dugotrajne povijesti akutnih psihotičnih epizoda, ali i kroničnih slabih psihosocijalnih prilagodbi. Shizofrenija je kompliciran dijagnostički entitet sa značajnim razlikama u kliničkoj prezentaciji bolesti, odgovoru na lijekove i tijeku bolesti (Bray i sur., 2010). Iako se neurobiološka podloga shizofrenije istražuje duže od jednog stoljeća, do danas nije sasvim poznata definitivna etiopatogeneza shizofrenije. To i nije čudno budući da je shizofrenija karakterizirana heterogenom kliničkom slikom, različitim simptomima, a ta fenotipska heterogenost odražava heterogenost patoloških mehanizama koji je izazivaju. No, neki su nalazi, kao što su određeni neuroanatomski i neurokemijski poremećaji, poznati. Prema Brayu i sur. (2010.), neuroanatomske promjene uključuju opće povećanje lateralnih ventrikula i relativno manje smanjenje volumena cijelog mozga, za koje se smatra da su neurorazvojnog porijekla. Neuropatološke promjene uključuju suptilne citoarhitektonske promjene hipokampusa i prefrontalnog korteksa i jače smanjenje volumena tih regija. Neurokemijske ili neurotransmitorske promjene uključuju promjene subkortikalne dopaminergičke aktivnosti za vrijeme akutne psihotičke faze bolesti koje se slažu sa dokazanom efikasnošću antipsihotika jer ti lijekovi djeluju putem dopaminergičkih receptora i liječe pozitivne simptome shizofrenije (Bray i sur., 2010.). Postoji mnoštvo različitih podataka o postojanju značajne povezanosti između shizofrenije i određenog rizičnog alela nekog gena, čija je funkcija vezana za pretpostavljenu neurobiološku podlogu shizofrenije. Jednako tako postoji i mnoštvo podataka o nedostatku bilo kakve povezanosti tih istih gena i shizofrenije. Sigurno je da taj odnos svakako nije jednostavan jer, radi komplesknosti i heerogenosti kliničke slike shizofrenije, nije niti moguće da jedan rizični alel određenog gena bude dovoljan za nastanak shizofrenije. Budući da je shizofrenija poligenska bolest, za razvoj shizofrenije je nužno da osoba nosi različite rizične alele koji su udruženi s različitim rizičnim čimbenicima iz okoline (DiForti i sur., 2007.). Najnoviji GWAS-ovi su utvrdili nekoliko gena koji su povezani s rizikom pojave shizofrenije. Jako je važno u nova istraživanja uključiti bioinformatičke analize genetskih podataka i usporediti rezultate koji upućuju na određene rizične varijante gena na svim razinama (molekularnoj, staničnoj i sistemskoj), a sve kako bi se poboljšalo razumijevanje osnovnih neurobioloških mehanizama nastanka shizofrenije (Bray i sur., 2010.). Kako je shizofrenija izrazito heterogen poremećaj, za pretpostaviti je da je i neurobiološka podloga te bolesti izrazito heterogena, ali može biti slična i podlogama drugih bolesti, kao što su bipolarni afektivni poremećaj ili autizam. Naime, pronađeni su zajednički rizični geni i njihove učestale varijante (SNP-ovi) za shizofreniju i bipolarne poremećaje, a studije koje su istraživale CNV-ove, otkrile su preklapanja između shizofrenije i autizma (O'Donovan i sur., 2009.). Također se ističe da rizični aleli bolesti obično imaju malu snagu za izazivanje bolesti, dok s druge strane neki vrlo rijetki CNV-ovi posjeduju veliku snagu za rizik razvoja bolesti Za razumijevanje etiologije shizofrenije potrebne su studije s velikim brojem uključenih bolesnika i kontrolnih ispitanika, a sve u svrhu pronalaska rizičnih alela koji pridonose riziku razvoja shizofrenije.

Tobacco smoking is a global health problem with far reaching consequences. Substances from tobacco smoke may affect brain functions via several neurotransmitters. Tobacco smoking is associated with various somatic and neuro-psychiatric disorders, altered behaviors and might represent a risk factor for suicide. A myriad of factors including environmental, biological and genetic factors are responsible for smoking behavior, smoking initiation, regular tobacco use, and nicotine dependence. The studies of allelic variations in genes involved in acetylcholine and dopamine pathways are aimed at finding a possible association between particular candidate genes and smoking. Catechol-O-methyltransferase (COMT) is an enzyme involved in degradation of dopamine, epinephrine, norepinephrine and is considered a major risk factor for smoking. The most frequently studied variation in the COMT gene, COMT Val158Met polymorphism, is a SNP that involves a substitution of valine (Val) with methionine (Met). There are a lot of conflicting and inconclusive findings regarding smoking status and COMT variants. The present study evaluated the possible association between smoking and COMT Val158Met polymorphism in male and female schizophrenic patients (diagosis made according to SCID and DSM-IV criteria) and healthy subjects. All subjects were subdivided into smokers (subjects smoking  10 cigarettes per day) and nonsmokers (subjects who never smoked in their life). We found significant (2 test) differences in the Met/Met, Met/Val or Val/Val genotype frequency between male schizophrenic smokers and nonsmokers, and between healthy male smokers and nonsmokers, due to the higher frequency of Val/Val homozygotes in smokers. COMT variants did not differ significantly within female healthy or schizophrenic smokers and nonsmokers. There were no significant gender related differences in the frequency of the COMT variants between male and female smokers and nonsmokers. The significant association between COMT variants and smoking suggested that Val/Val genotype might be a risk factor for smoking.

Introduction: Chronic alcoholism is frequently associated with sleep disorders, disrupted sleep, insomnia, mood instability and craving. Namely, alcohol affects sleep latency, disrupts the sleep periods during night, affects rapid eye movement sleep and elicits frequent episodes of wakefulness, and frequent shifts between sleep stages. Alcoholics often experience insomnia, especially during the withdrawal syndrome. In addition, insomnia is a risk factor for relapse into addiction of alcohol. Although the consumption of alcohol may improve sleep latency at the beginning of alcohol abuse, at later stages chronic alcoholism is associated with poor sleep quality, early wakening, and insomnia. Numerous neurotransmitters have been implicated in regulation of normal and irregular sleep behavior, and in the etiology of alcoholism. Serotonin (5-hydroxytryptamine, 5-HT) has a major role in the control of many physiological and pathological functions and behaviors, including sleep, wakefulness, arousal states, vigilance behaviors, synchronization of the biological clock and circadian rhythmicity. Serotonergic neurotransmission from the dorsal raphe is associated with arousal and is turned off during sleep. Serotonin has a role in etiology of alcoholism. Central 5-HT synaptosomes and platelets similarly store, release and metabolize 5-HT, and therefore blood platelets might be used as a limited peripheral model for the central 5-HT synaptosomes. Platelet 5-HT concentration has been proposed to represent a biomarker for particular symptoms in psychiatric disorders, to be reduced in chronic alcoholics, and in subjects with disturbed sleep. Materials and Methods: Platelet 5-HT concentration was determined in male and female patients with chronic alcoholism, subdivided into patients with or without insomnia with a spectrofluorimetric method. Clinical diagnosis of alcohol dependence made according to the DSM-IV criteria, using Structured Clinical Interview. Insomnia was evaluated using the items 4, 5 and 6 from the Hamilton Rating Scale for Depression, and alcoholics were subdivided into those with early, middle and late insomnia. Results: Male alcoholic patients with middle insomnia had significantly lower platelet 5-HT concentration compared to male alcoholics without middle insomnia. Platelet 5-HT concentration did not differ significantly among male alcoholic patients with or without early or late insomnia, or between female alcoholic patients with or without early, middle and late insomnia. Conclusions: Since ethanol improves the onset of sleep, while at the same time the duration of sleep is disturbed, lower platelet 5-HT concentration in middle insomnia suggest that this peripheral marker is altered in alcoholics with middle insomnia.

Aims: Alzheimer’s disease (AD) is prevalent, complex and progressive neurodegenerative disorder, characterized by heavy memory losses, losses of speech, reductions of the cognitive function, altered behavior, and inabilities of decision making. AD is the most frequent cause of dementia. The genetic risk factors for AD include mutations of genes for amyloid precursor protein, presenilins, apolipoprotein E gene, but also for brain derived neurotrophic factor (BDNF). BDNF is a neurotrophin that regulates neuronal development and function, cognition, learning, mood, behavior, and stress response. Since BDNF affects cholinergic, dopaminergic, and serotonergic neurotransmission, it has a role in the etiopathogenesis of different neuropsychiatric disorders including AD. Cognitive decline is associated with reduced BDNF levels. The BDNF gene contains a common, functional polymorphism, Val66Met that produces the substitution of valine (Val) to methionine (Met). It affects intracellular trafficking and activity-dependent secretion of BDNF. The Met allele is associated with reduced delayed episodic memory, poor working memory performance and impaired hippocampal function. BDNF Val66Met polymorphism was proposed, and opposed, to be a risk factor for AD. The aim of the study was to compare the distribution of Val66Met variants in male and female healthy persons, patients with mild cognitive impairment (MCI) and patients with AD. Methods: BDNF Val66Met was genotyped with RT-PCR method from DNA extracted from blood samples obtained from 211 AD patients, 20 MCI patients and 144 healthy age-matched controls, recruited at the Psychiatric Hospital Vrapce and Department of Neurology, Clinical Hospital Centre Zagreb. AD patients were further subdivided according to the early/ late onset of AD and presence/absence of psychotic symptoms. Results and conclusion: Patients with AD, MCI, early and late onset of AD, psychotic and non-psychotic AD, and healthy persons had similar frequency of the BDNF Val66Met variants. When divided by gender, significant differences in the frequency of genotypes, and Met carriers versus Val homozygotes were detected within male or female patients with psychotic AD. Although BDNF Val66Met was not confirmed as a susceptibility factor for AD, the results suggested a possible association between Met carriers of the BDNF Val66Met, psychotic symptoms of AD and gender in AD.

Posttraumatic stress disorder PTSD is frequent, multifactorial, complex polygenic psychiatric disorder, precipitated by a traumatic event. Since most individuals who experience traumatic stressors never develop PTSD, some other factors (biological, genetic, environmental, early experiences) are responsible for the resilience or vulnerability to develop PTSD. Molecular basis of PTSD is not completely clear, but it is assumed to involve the changes in different neuroendocrine (hypothalamic-pituitary-adrenal /HPA/ axis) and neurotransmitter (primarily serotonin, noradrenalin, dopamine) systems, and functional gene polymorphisms controlling the activity of the corresponding proteins. Genetic studies in PTSD are scarce, and genes related to HPA axis and dopamine were found to be associated with PTSD. Combat-related PTSD is especially pervasive form of PTSD. Our study determined monoamine oxidase (MAO-B intron 13 G/A), dopamine-beta-hydroxylase (-1021C/T DBH), catechol-o-methyltransferase (COMT val158/108met), brain derived neurotrophic factor (BDNF val66met), serotonin transporter (5HTT gene- linked polymorphic region, 5HTTLPR), and serotonin receptor (5HT2A 102T/C) polymorphisms in male Croatian war veterans with current and chronic combat related PTSD (diagnoses made using the SCID and DSM-IV criteria), with and without different psychiatric comorbid disorders, with aim to evaluate genetic risk factors associated to PTSD. No significant differences (chi-square test) were found in the frequencies of the genotypes or alleles for MAO-B, -1021C/T DBH, val158/108met COMT, val66met BDNF, 5HTTLPR and 102T/C 5HT2A between veterans with PTSD, veterans with PTSD and comorbidities and combat exposed veterans who did not develop PTSD. The lack of significant direct effects of genotypes of alleles on manifestation of PTSD did not support our hypothesis that biomarkers are altered in PTSD. Given the complexity of the clinical presentation of PTSD, future studies should elucidate the relationship between genetic risk factors and endophenotypes, i.e. smaller biological and psychological sub- symptoms of PTSD, that can serve as biomarkers of vulnerability and resilience.

Dosadašnja istraživanja serotoninskog sustava su pokazala da serotonin i njegovi receptori imaju između ostaloga važnu ulogu u regulaciji unosa hrane, apetita i tjelesne težine. Poremećena aktivnost i funkcija serotoninskog sustava se povezuje s razvojem psihijatrijskih poremećaja (depresija shizofrenija, posttraumatski stresni poremećaj /PTSP/). Promjene apetita i tjelesne težine često su prisutne u psihijatrijskih bolesnika, a mogu se javiti i kao nuspojava tijekom liječenja psihofarmacima. Serotoninski receptori tipa 2A (5-HT2A receptori) se nalaze na membrani postsinaptičkog neurona, u stijenci krvnih žila i na membrani trombocita. U depresiji, shizofreniji i PTSP dokazana je promjenjena funkcija 5-HT2A receptora. Mjesto su djelovanja antidepresiva i atipičnih antipsihotika. Gen 5HT2A receptora je smješeten na dugom kraku kromosoma 13 i sadrži tri eksona i dva introna. Rezultati usporedbe funkcije 5HT2A receptora i T102C polimorfizma gena za 5HT2A receptore upućuju da bi T alele bio povezan s povećanim brojem (funkcijom) 5HT2A receptora u zdravih osoba. Najnovija molekularna istraživanja istražuju da li bi određivanje genskih varijanti 5-HT2A receptora moglo poslužiti u personalnoj medicini u predviđanju individualnog dobrog ili lošeg terapijskog učinka psihofarmaka. Usprkos velikom broju istraživanja dobiveni rezultati nisu potvrdili pretpostavke o povezanosti genskih varijanti 5-HT2A receptora s etiologijom psihičkih poremećaja ili s terapijskim učinkom psihofarmaka. Suvremeni način života koji uključuje kaloričnu prehranu uz istovremeno smanjenu fizičku aktivnost najčešći su uzrok porasta broja osoba s prekomjernom tjelesnom težinom. Debljina smanjuje kvalitetu života i predstavlja ozbiljnji zdravstveni problem zbog povećanog rizika razvoja šećerne bolesti, metaboličkog sindroma, hipertenzije, srčanih i malignih oboljenja. Najnovija molekularna istraživanja su pokazala povezanost između polimorfizama gena serotoninskih 5-HT2A i 5-HT2C receptora, poremećaja hranjenja, pretilosti, povećanog indeksa tjelesne mase i izostanka supresije lučenja kortizola u deksametazonskom testu./ Rezultati naših istraživanja su pokazali da je distribucija genotipova 5HT2A gena u hrvatskih zdravih ispitanika u skladu s literaturnim podacima o distruibuciji u populaciji euroazijskog porijekla. Dobiveni preliminarni rezultati ne potvrđuju pretpostavke da je prekomjerni indeks tjelesne mase u veterana s PTSP-om i u ratnih veterana bez PTSP-a povezan s koncentracijom trombocitnog serotonina i C alelom 102T/C polimorfizma 5-HT2A gena. Neophodno je daljnje istraživanje povezanosti serotoninskog sustava, i njegovih receptora u etiologiji i liječenju psihičkih poremećaja.

Smatra se da su serotonin i njegovi receptori uključeni između ostalog i u regulaciju unosa hrane, apetita, tjelesne težine, lučenja kortizola i odgovora na stres. Najnovija molekularna istraživanja su pokazala povezanost između polimorfizma gena serotoninskog receptora tipa 2A (5-HT-2A), poremećaja hranjenja, pretilosti, indeksa tjelesne mase (ITM) i supresije lučenja kortizola u deksametazonskom testu, što upućuje da bi promjene aktivnosti serotoninskog sustava mogle biti prisutne u stresom izazvanim poremećajima kao što je posttraumatski stresni poremećaj (PTSP). Pretpostavlja se da stres i čimbenici okoline kao što su kalorična prehrana i smanjena fizička aktivnost pridonose porastu broja osoba s prekomjernom tjelesnom težinom. Debljina smanjuje kvalitetu života i predstavlja ozbiljnji zdravstveni problem zbog povećanog rizika razvoja šećerne bolesti, metaboličkog sindroma, hipertenzije, kardiovaskularnih i malignih oboljenja. Cilj istraživanja je bio odrediti a) koncentraciju trombocitnog serotonina, b) distribuciju genotipova i alela T102C polimorfizma 5HT-2A gena i c) usporediti navedene biokemijske i molekularne varijable s indeksom tjelesne mase u 66 veterana Domovinskog rata sa PTSP-om i 53 veterana bez PTSP-a . Ispitanici su bili veterani Domovinskog rata podjednake dobi i borbenog iskustva. Dijagnoza PTSP-a je postavljena pomoću Međunarodnog neuropsihijatrijskog intervjua temeljenog na DSM-IV kriterijima. ITM je izračunat iz omjera tjelesne težine (u kg) i kvadrata tjelesne visine (u metrima). Ispitanici su podijeljeni na one s idealnom (ITM od 18, 5 do 24, 9 kg/m2), povišenom (ITM 25 do 29, 9 kg/m2) i prekomjernom (ITM > 30 kg/m2) tjelesnom masom. Na temelju 12. pitanja Hamiltonove ocjenske ljestvice za depresiju veterani s PTSP-om su dodatno podijeljeni na one bez (broj bodova 0) ili s gubitkom apetita (broj bodova 1). Koncentracija trombocitnog serotonina je određena spektrofluorimetrijskom metodom. Ispitanicima je izolirana DNA koja je podvrgnuta PCR-RFLP analizi, kako bi se utvrdila distribucija alela i genotipova 102 T/C polimorfizma 5-HT-2A receptora. Za statističku obradu rezultata korištena je jednosmjerna analiza varijance. Učestalost pojedinih genotipova i alela u uzorku te značajnost odstupanja uočene distribucije od očekivane (Hardy-Weinbergova distribucija) određena je pomoću χ 2-testa. Distribucija osoba s idelanim, povišenim i prekomjernim ITM bila je podjednaka u skupini ratnih veterana sa PTSP-a kao i u skupini onih koji nisu oboljeli od PTSP-a. Povišena ili prekomjerna tjelesna masa bila je prisutna u 75% veterana bez PTSP-a i u 67% veterana s PTSP-om. Rezultati su pokazali da nema povezanosti između koncentracije trombocitnog serotonina, ITM i promjene apetita. Koncentracija trombocitnog serotonina bila je podjednaka u ratnih veterana sa ili bez PTSP-a neovisno o njihovom ITM. Distribucija CC, CT, TT genotipova 102T/C polimorfizma 5-HT-2A gena bila je podjednaka (p=0, 343 ; χ 2-test) u ratnih veterana sa ili bez PTSP-a. U ratnih veterana bez PTSP-a C alel bio je prisutan u 63% ispitanika, a u oboljelih od PTSPa u 54% ispitanika. Frekvencija pojavljivanja genotipova (p=0, 616 i p=0, 893) i alela (p=0, 484 i p=0, 697) nije bila povezana s ITM ratnih veterana bez PTSP-a kao i onih oboljelih od PTSP-a. Dobiveni preliminarni rezultati ne potvrđuju pretpostavke da je prekomjerni ITM u veterana s PTSP-om i u ratnih veterana bez PTSP-a povezan s koncentracijom trombocitnog serotonina i C alelom 102T/C polimorfizma 5-HT-2A gena. Neophodno je daljnje istraživanje povezanosti serotoninskog sustava, gena 5-HT-2A receptora i ITM na većem broju ispitanika.

Aim was to compare in a multi-centric study the frequency of alleles and genotypes in BDNF val66met polymorphism in ethnically homogenous Caucasian (from Croatia) and ethnically homogenous Asian (from South Korea) healthy subjects, as inter-population differences in BDNF val66met may be responsible for the divergent findings in genetic and association studies. BDNF val66met was genotyped in 800 (556 Croatian and 244 Korean) healthy subjects. Frequencies of alleles and genotypes were evaluated using a chi-square test. The frequencies for genotypes ( 2=114.69 ; df=2 ; p

Postraumatski stresni poremećaj (PTSP) je kronični dugotrajni teški poremećaj, koji nastaje nakon izlaganja ekstremnom traumatskom događaju. Jedan od važnih karakterističnih simptoma te bolesti jest ponovno proživljavanje traumatskog događaja kroz uznemiravajuće snove, koji su popraćeni nesanicom i noćnim morama. Biološka podloga PTSP- a, ali i poremećaja spavanja, uključuje poremećeno funkcioniranje neuroendokrinih (os hipotalamus- hipofiza-nabubrežna žlijezda) i neurotransmitorskih (serotonin ili 5-HT, noradrenalin) sustava. Trombociti i središnji 5-HT sinaptosomi dijele slične biokemijske procese te se trombociti koriste kao periferni model za središnje 5-HT neurone. Serotoninski transporter (5-HTT) nadzire djelovanje 5-HT unutar sinapse, a na membrani trombocita služi za unos 5-HT iz krvi. Gen za serotoninski transporter (5HTT) važan je za regulaciju 5-HT neurotransmisije. Funkcionalni polimorfizam serotoninskog transportera (5-HTTLPR) javlja se u promotorskoj regiji gena 5HTT. Putem dva alela: kratkog S i dugačkog L alela 5-HTTLPR različito modulira aktivnost 5-HTT. Cilj našeg rada bio je odrediti koncentraciju trombocitnog 5- HT u krvi i distribuciju 5-HTTLPR genotipova (LL, LS i SS) i alela (L i S) u veterana Domovinskog rata s PTSP-om koji su bili podijeljeni na one sa ili bez nesanice, u svrhu stjecanja novih spoznaja o neurobiologiji poremećaja spavanja u PTSP-u. U 131 veterana Domovinskog rata s kroničnim PTSP-om (dijagnosticiranog pomoću Međunarodnog neuropsihijatrijskog intervjua koji se temelji na DSM-IV kriterijima), određena je koncentracija 5- HT u trombocitima i genotip 5HTT pomoću fluorimetrijske i PCR metode. Veterani s PTSP-om bili su podijeljeni na one sa ili bez nesanice koja je procijenjena pomoću strukturiranog psihijatrijskog intervjua, i pomoću Hamiltonove ocjenske ljestvice za depresiju (HAMD), pitanje 4, 5 i 6: rana, srednja i kasna nesanica ; pomoću Hamiltonove ljestvice za anksioznost (HAMA, pitanje 4: nesanica), i Kliničke ljestvice za PTSP (CAPS, nesanica). Svi su ispitanici bili podijeljeni na one bez nesanice (broj bodova 0) i one sa nesanicom (broj bodova ³ ; 1). Statistička obrada podataka učinjena je pomoću jednosmjerne analize varijance (ANOVA-e) i Tukeyevog testa (koncentracija trombocitnog 5-HT), dok je učestalost genotipova i pojedinih alela u uzorku te značajnost odstupanja uočene distribucije od očekivane (Hardy-Weinbergova distribucija) određena pomoću χ 2-testa. Jednosmjerna ANOVA je pokazala kako nema značajnih razlika u koncentraciji trombocitnog 5-HT između veterana s PTSP-om, sa ili bez nesanice, mjerenih brojem bodova na skalama HAMD ili HAMA. Također nisu pronađene značajne razlike u koncentraciji trombocitnog 5-HT kod veterana s PTSP-om sa nesanicom, podijeljenih na one sa 5, 6 ili 7 bodova na ljestvici CAPS. Međutim, bio je vidljiv trend prema nižim vrijednostima trombocitnog 5-HT u veterana s izraženijom nesanicom prema onima koji nisu imali nesanicu. Učestalost pojavljivanja 5HTTLPR genotipova i alela bila je značajno povezana sa nesanicom u veterana s PTSP-om. Distribucija genotipova ( 2 = 10.548 ; df=4 ; P=0.032) i alela ( 2 = 9.596 ; df=2 ; P=0.008) značajno se razlikovala između veterana sa ili bez rane nesanice. Distribucija alela značajno se razlikovala između veterana sa ili bez srednje ( 2 =6.828 ; df=2 ; P=0.033) ili kasne ( 2 =8.060 ; df=2 ; P=0.018) nesanice. Da bi utvrdili koji su aleli odgovorni za te razlike, veterani s PTSP-om podijeljeni na S nosioce (SS + LS) prema LL homozigotima. Veterani s 2 boda sa ranom ( 2 =8.730 ; df=2 ; P=0.013) i srednjom ( 2 =6.109 ; df=2 ; P=0.047) nesanicom bili su češće S nositelji od LL homozigota. Naši su preliminarni podaci pokazali kako se koncentracija trombocitnog 5-HT ne razlikuje između veterana s PTSP-om podijeljenih na one sa ili bez nesanice, no pokazao se trend k sniženim vrijednostima trombocitnog 5-HT u veterana s PTSP-om koji su imali izraženu ranu, srednju ili kasnu nesanicu. Istraživanja funkcionalnog polimorfizma serotoninskog transportera (5-HTTLPR) pokazalo je značajne razlike u pojavi genotipova LL, LS i SS između veterana sa ili bez rane nesanice, dok su se aleli L ili S značajno razlikovali kod veterana sa ranom, srednjom i kasnom nesanicom. Budući da su te razlike bile izazvane većom učestalošću S nosioca, ti su rezultati potvrdili naša očekivanja da će veterani s PTSP-om sa poremećajima spavanja, odnosno sa izraženom nesanicom, biti češći S nosioci od LL homozigota, jer je S alel vezan sa smanjenom aktivnošću 5-HT sustava i nižom koncentracijom trombocitnog 5-HT. Naši preliminarni rezultati upućuju na potrebu povećanja broja ispitanika sa poremećajima spavanja. U zaključku, treba nastaviti istraživati biološke i genetske pokazatelje poremećaja spavanja i nesanice u skupinama ispitanika s PTSP- om kako bi se što prije otkrila etiopatogeneza poremećaja spavanja u PTSP-u, u svrhu boljeg razumijevanja i adekvatnog liječenja.

Amyotrophic lateral sclerosis is increasingly recognized as a multisystem disorder which includes motor system deficit and non-motor impairments in a spectrum of clinical features of frontotemporal dementia (FTD). The overlap between cognitive impairment and behavioral features is demonstrated in up to 50% of ALS patients. Behavioral features are mostly due to changes in serotonergic and catecholaminergic system. Therefore, we aimed to identify gene polymorphisms for proteins involved in serotonin and catecholamine metabolism and function with the emphasis on executive function in ALS patients. In a prospective study, 18 ALS patients (10 male, 60.5+/-5.8 yrs) defined by El Escorial Criteria were investigated. ... We did not find correlations between gene polymorphisms and variables of executive functional test. A sizeble proportion of ALS patients' showed behavioural and cognitive changes within a spectrum of FTD.

A functional catechol-o-methyltransferase (COMT Val158/108Met) polymorphism, a valine (Val) to methionine (Met) substitution, has been associated with cognitive processing in the normal brain, older age, mild cognitive impairment (MCI), various dementias and cognitive disruptions in schizophrenia. COMT is involved in the breakdown of dopamine and other catecholamines, especially in the frontal cortex ; hence the carriers of Met allele, with the lower enzymatic activity, are expected to perform better on particular neurocognitive tests. Peripheral blood samples were collected from 40 dementia and 13 MCI patients. The determination of the neurological status of the dementia patients utilized the MMSE, NPI, ADAS-COG, CDT, World pairs learning and recall/ Picture pairs learning and recall test and Visual attention test performed by an experienced neurologist. DNA from blood was extracted using the DNeasy Blood and Tissue Kit (Qiagen). In DNA samples COMT polymorphism was genotyped by a TaqMan (Applied Biosystems) analysis. The results, expressed as means &plusmn ; ; SD, were evaluated using one-way ANOVA followed by the Tukey’ s test. The Hardy-Weinberg analysis was used to test the equilibrium of the population. The differences in the genotype and allele frequencies were evaluated using a  2 test. Patients with dementia and MCI differed significantly (p=0.035-0.001, ANOVA) in age, duration of disease, MMSE, modified MMSE, ADAS, NPI, NPI apathy and CDT scores. The observed genotype distribution in patients with dementia ( 2=0.14 ; d.f.=1 ; P=0.933) and MCI ( 2=0.00 ; d.f.=1 ; P=1.000) did not differ significantly from the expected Hardy– Weinberg equilibrium. In patients with dementia, but not with MCI, significant (p=0.016-0.041, ANOVA) genotype-induced differences were found in scores for MMSE, modified MMSE, VAT duration of numbers test, VAT time of response to numbers test, VAT average response to numbers test and WPLCR/PPLR unanswered. Carriers of Met/Met genotype had significantly (p=0.015-0.037, Tukey's test) lower scores of MMSE or modified MMSE, significantly longer time to respond to VAT duration of numbers test, VAT time of response to numbers test and VAT average response to numbers test, and significantly greater number of unanswered questions to WPLCR/PPLR when compared to Met/Val or Val/Val genotypes. Our preliminary data showed significantly impaired performance in several neurocognitive tests in carriers of Met/Met genotype in patients with dementia, but not in patients with MCI, compared to either Met/Val or Val/Val genotype carriers. Although Met/Met genotype with more dopamine available in the frontal cortex should be associated with better neurocognitive test results than Met/Val or Val/Val genotype, our data on demented patients did not confirm this hypothesis. Further study on larger sample of patients is needed to clarify the role of COMT polymorphism in cognitive functions.

Introduction: Brain derived neurotrophic factor (BDNF) plays an important role in neuronal survival, differentiation, and synaptic plasticity in the brain. Reduced BDNF levels are found in dementia and cognitive decline. BDNF is controlled by a functional polymorphism, which consists of a substitution of valine (Val) into methionine (Met). This BDNF val66met polymorphism has been implicated in lower depolarization-induced production of BDNF, lower n-acetyl asparatate content, and reduced hippocampal activation during memory processing. The Met allele has been associated with reduced delayed episodic memory or working memory performance, but also with enhanced verbal reasoning ability. Aim: The hypothesis was that BDNF genetic variants may be associated with cognitive function in patients with dementia and mild cognitive impairment (MCI). Methods: A Val66Met polymorphism of the BDNF-gene was studied in 40 patients with dementia and in 13 patients with mild cognitive impairment (MCI). The association of BDNF val66met with neurological and cognitive status in patients with dementia and MCI was examined using the MMSE, NPI, ADAS-COG, CDT, Word pairs learning and recall/ Picture pairs learning and recall test and Visual attention tests. DNA from blood was extracted using the DNeasy Blood and Tissue Kit (Qiagen). In DNA samples BDNF polymorphism was genotyped by a TaqMan (Applied Biosystems) analysis. Results were evaluated using one-way ANOVA followed by the Tukey’ s test. The Hardy-Weinberg analysis was used to test the equilibrium of the population. The differences in the genotype and allele frequencies were evaluated using a  2 test. Results: The genotype and allele frequencies for Val66Met polymorphism did not differ significantly between control subjects, and patients with dementia or MCI. Patients with dementia and MCI differed significantly (p=0.035-0.001, ANOVA) in age, duration of disease, MMSE, modified MMSE, ADAS, NPI, NPI apathy and CDT scores. When subdivided according to the BDNF variants, patients with dementia differed significantly (F=8.422 ; p=0.012) only in the NPI disinhibition scores, while patients with MCI had significantly different (F=4.997 ; p=0.047) scores on Word pairs learning and recall/ Picture pairs learning and recall test (time of un-correct answers). The observed genotype distribution in patients with dementia ( 2=0.97) and MCI ( 2=0.69) did not differ significantly (P 0.05) from the expected Hardy– Weinberg equilibrium. Conclusion: The results from this preliminary study, showing that carriers of Val/Val genotype had better NPI disinhibition scores in dementia and shorter time of incorrect answers in MCI, are in line with the lower BDNF activity in Met/Met carriers. Although homozygosity for the Val allele was reported to confer an increased risk for dementia, no significant differences were found in the frequency of BDNF variants among patients or between patients and control subjects.

Biološki i genetski pokazatelji i suicidalno ponašanje u posttraumatskom stresnom poremećaju Nela Pivac1, Gordana Nedić1, Maja Mustapić1, Dorotea Muck-Šeler1, Mirjana Grubišić-Ilić2, Dragica Kozarić-Kovačić2 1Zavod za molekularnu medicinu, Institut Ruđer Bošković, Zagreb, Bijenička 54 2Klinička bolnica Dubrava, Odjel psihijatrije, Referentni centar Ministarstva zdravstva i socijalne skrbi Republike Hrvatske za poremećaje uzrokovane stresom, Regionalni centar za psihotraumu Zagreb, Zagreb, Avenija Gojka Šuška 6 Posttraumatski stresni poremećaj (PTSP) je psihijatrijska bolest karakterizirana prisustvom tri skupine simptoma (ponovno proživljavanje, izbjegavanje i povećana pobuđenost). PTSP je praćen različitim komorbidnim poremećajima i poremećajima ponašanja, a često i suicidalnim ponašanjem. Neurobiološka podloga PTSP-a veže se za promijenjeno funkcioniranje različitih neurotransmitorskih (dopamin, noradrenalin, serotonin (5-HT) i neuroendokrinih sustava. Suicidalno ponašanje je također povezano s promjenama dopaminergičke, noradrenergičke, i 5-HT neurotransmisije. Budući da biološka i genetska podloga PTSP-a i suicidalnog ponašanja još uvijek nije jasna, istraživanja bioloških i genetskih pokazatelja mogu poboljšati razumijevanje nastanka i prevencije PTSP-a i suicidalnih pokušaja. Monoaminooksidaza (MAO) je enzim koji katalizira deaminaciju različitih neurotransmitora (dopamin, 5-HT, noradrenalin) i egzogenih amina. Javlja se u dva oblika (MAO-A i MAO-B). Trombocitna MAO je MAO-B oblika i njezina aktivost se često koristi kao pokazatelj različitih poremećaja ponašanja kao što je suicidalno, te nekih psihijatrijskih poremećaja. Pretpostavljalo se da je polimorfizam koji se nalazi u ponavljajućoj regiji 13. introna gena za MAO-B funkcionalan. Kod tog se polimorfizma radi se o promjeni jedne baze (A ili G ) smještene 36 bp uzvodno od granice 13. introna i 14. egzona. Istraživanja o njegovoj funkcionalnosti nisu jedinstvena, jer su pokazala da nosioci alela G imaju povišenu ili nepromijenjenu aktivnost MAO-B u trombocitima. Katehol-o-metil transferaza (COMT) je enzim koji katabolizira dopamin, noradrenalin i adrenalin i rizični je čimbenik za razne psihijatrijske poremećaje, te poremećena ponašanja kao što su ljutnja, agresija i suicidalnost. Postoji funkcionalni polimorfizam gena COMT (zamjena G u A u egzonu 4 gena za COMT lociranog na kromosomu 22 (regija 22q11.1-q11.2) koji rezultira zamjenom valina u metionin u proteinu na položaju 158. Nosioci valin-alela imaju povećanu aktivnost COMT-a, dok nosioci metionin-alela imaju smanjenu aktivnost COMT-a. Serotoninski transporter (5-HT transporter, 5-HTT) je proteinski prijenosnik koji na završetcima 5-HT aksona prekida djelovanje 5-HT unutar sinapse, dok na membrani trombocita služi za unos 5-HT iz krvi. Gen za serotoninski transporter (5HTT) smješten je na 17 kromosomu (regija 17q11.-q12) i važan je za regulaciju 5-HT neurotransmisije te za djelovanje antidepresivnih lijekova. Postoji polimorfizam u promotorskoj regiji gena 5HTT, i naziva se 5-HTTLPR, i najčešći aleli jesu alel sa 14 ponavljajućih jedinica ili kratki (short S) alel te alel sa 16 ponavljajućih jedinica ili dugi (long L) alel. Smatra se da je alel S udružen s pojavom depresije, suicidalnim idejama i suicidalnim pokušajima u osoba koje su nedavno bile izložene traumatskim događajima. Cilj ovog istraživanja bio je odrediti aktivnost MAO-B u trombocitima i distribuciju genotipova i alela za MAO-B, COMT i 5HTT kod oboljelih od PTSP-a, podijeljenih prema suicidalnom ponašanju na suicidalne i nesuicidalne osobe. U veterana Domovinskog rata s kroničnim PTSP-om dijagnosticiranom prema DSM-IV kriterijima, određeni su aktivnost MAO-B pomoću fluorimetrijske metode te genotipovi MAO-B i COMT pomoću real time PCR metode. 5HTTLPR je određen pomoću lančane reakcije polimerazom (PCR) te razdvajanjem amplificiranog produkta na 2%-tnom agaroznom gelu. Veterani s PTSP-om bili su podijeljeni na one sa ili bez suicidalnog ponašanja. Suicidalno ponašanje procijenjeno je pomoću strukturiranog psihijatrijskog intervjua, i pomoću Hamiltonove ocjenske skale za depresiju, pitanje 3- suicidalnost. Svi su ispitanici bili podijeljeni na nesuicidalne (broj bodova 0) i suicidalne ( broj bodova ³ ; 1). Statistička obrada podataka učinjena je pomoću Kruskal Wallisove analize varijance rangova i Mann Whitney-evog testa i dvostruke analize varijance (aktivnost trombocitne MAO-B), dok je učestalost genotipova i pojedinih alela u uzorku, te značajnost odstupanja uočene distribucije od očekivane (Hardy-Weinbergova distribucija) određena pomoću χ 2-testa. Veterani oboljeli od PTSP-a sa ili bez suicidalnog ponašanja imali su značajno različitu aktivnost trombocitne MAO-B, no te su razlike nastale radi pušenja cigareta (dakle pušačkog statusa), a ne zbog prisutnosti suicidalnog ponašanja Naime, nije bilo značajnih razlika u aktivnosti trombocitne MAO-B između suicidalnih i nesuicidalnih nepušača i pušača. Pokazani su značajni učinci pušenja, ali ne i genotipa ili interakcije između genotipa i pušenja, na aktivnost trombocitne MAO-B. Učestalost pojavljivanja genotipa MAO-B bila je slična među suicidalnim i nesuicidalnim veteranima. Polimorfizam na 13. intronu MAO-B gena nije bio funkcionalan, i nije utjecao na aktivnost MAO-B u trombocitima svih ispitanika. Rezultati upućuju da aktivnost MAO-B u trombocitima i polimorfizam na 13. intronu gena MAO-B nisu dobri pokazatelji suicidalnog ponašanja u veterana s PTSP-om. Istraživanja polimorfizma gena za COMT i 5-HTT pokazala su kako nema značajnih razlika u pojavi genotipova AA, AG i GG ili alela G i A za COMT ili genotipova LL, LS i SS i alela L ili S za 5-HTT između suicidalnih i nesuicidalnih veterana s PTSP-om. Nisu potvrđena očekivanja da će suicidalni veterani s PTSP-om bili su češći nosioci metionin alela koji je povezan sa sniženom aktivnosti COMT-a, a ta smanjena aktivnost izaziva povećan dopaminergički utjecaj na prefrontalni korteks, i posljedično poremećaje emocionalnog procesiranja te agresivno i suicidalno ponašanje. Nadalje, nije pronađena povezanost između S alela i suicidalnog ponašanja u veterana s PTSP-om. Naši dobiveni rezultati upućuju na potrebu povećanja broja ispitanika i ne isključuju mogućnost da su ti biološki i genetski pokazatelji povezani s jače izraženim suicidalnim ponašanjem, odnosno suicidalnim pokušajima. U zaključku, treba nastaviti istraživati biološke i genetske pokazatelje suicidalnog ponašanja u usko definiranim skupinama ispitanika s PTSP-om kako bi se što prije otkrile osobe koje su sklone suicidalnom ponašanju, u svrhu bolje prevencije suicidalnih pokušaja i adekvatnog liječenja.

Amyotrophic lateral sclerosis (ALS) is a progressive and ultimately fatal neurodegenerative disease. The overlap between ALS and dementia is demonstrated by the presence of cognitive, behavioral dysfunction and change of personality in up to 50% of ALS patients. Behavioral features are mostly due to changes in catecholaminergic and serotonergic system. To identify genetic correlates of cognitive changes with the emphasis on executive function in ALS patients. In a prospective study, two tests of executive functions (Controlled oral word association - FAS test ; Tower of London (TOL), and a screening instrument for dementia were applied on 15 ALS patients (9 male, 60.5± 5.8 years), as defined by El Escorial Criteria. -1021 C/T polymorphism of DBH gene, 102 C/T polymorphism of 5-HT2A receptor gene, val66met polymorphism of COMT gene and val158/108met polymorphism of BDNF gene were correlated with a cognitive tests. ALS patients carrying GG, GA and AA genotype of the BDNF gene polymorphism were 73%, 20% and 7%, respectively. The frequency of GG, GA, AA genotype for COMT gene polymorphism was 33%, 53% and 14%, respectively. The DBH gene polymorphism distribution was 47%, 47% and 6% for CC, CT and TT genotype, respectively. The frequency of CC, CT, TT genotype for 5-HT2A gene polymorphism was 30%, 60% and 10%, respectively. 57% of patients showed deficient word generation capability. 21% were impaired on TOL Total move score and 33% on TOL Total rules violation score. 40% were impaired at DRS II Conceptualization subtest and 20% on DRS-II Memory subtest. No significant (p>0.05) relationship between genes polymorphism and variables of executive functional tests was found. The preliminary findings reveal a tendency for executive cognitive deficits in group of ALS patients. The genetic variation may influence behavior and memory conditions. Further studies on a larger sample, however, are needed in order to confirm it.

Background: Attention-deficit/hyperactivity disorder (ADHD) is a complex and clinically heterogeneous, polygenic psychiatric disorder, highly prevalent in children, frequently associated with different comorbidities. The ethiology of ADHD is thought to be associated with deficits in dopaminergic, noradrenergic and serotonergic systems. Central serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter and neuromodulator in the CNS, involved in the aetiology of psychiatric disorders and pathological behaviours. Central 5-HT regulates cognitive functions, violence, hostility, impulsivity and aggression, and reduced levels of central 5-HT were found in ADHD and depression. Blood platelets share similarities, but also differences, with the central 5-HT neurons. Peripheral 5-HT markers were reported to be decreased, increased or unaffected in ADHD, while platelet 5-HT concentration was altered in depressed, anxious, hostile, impulsive and aggressive subjects. Aim: The aim of the study was to determine platelet 5-HT concentration among boys and girls with ADHD, with symptoms of depression, anxiety and combination of depression and anxiety, and to compare platelet 5-HT concentration with the values in control boys and girls. Methods: ADHD was diagnosed accoriding to DSM-IV criteria (APA 2000), clinical interview, physical examination and Conner’ s Rating Scale for Parents and Teachers ; depressive and anxious symptoms were assessed using State-Trait Anxiety Inventory for Children (STAIC-M), and Beck Depression Inventory Children's Depression Inventory (CDI-M and CDI-Z). Statistics: The results, expressed as means &plusmn ; SD, were evaluated using one-way or two-way analysis of variance (ANOVA) followed by followed by Tukey multiple comparison test. Results: There were no significant (F=0.842 ; df=3, 108 ; p=0.474, one-way ANOVA) differences in platelet 5-HT concentration between boys and girls with ADHD and control boys and girls. No significant effect of diagnosis or gender, and no significant interaction between diagnosis and gender on platelet 5-HT concentration was found (F=0.042 ; df=1, 77 ; p=0.840 ; two-way ANOVA). Age did not differ significantly (F=1.456 ; df=3, 108 ; p=0.231, ANOVA) between boys and girls with ADHD or control boys and girls. Platelet 5-HT concentration was significantly (F=3.42 ; df=4, 55 ; p=0.014, one-way ANOVA) different between children with ADHD who did not show depressive or anxious symptoms, children with ADHD with depressive, anxious and combination of depressive and anxious symptoms. Children with ADHD and depressive symptoms had significantly higher platelet 5-HT concentration than ADHD children without depressive or anxious symptoms (P=0.045 ; Tukey's test), than ADHD children with combination of depressive and anxious symptoms (P=0.008 ; Tukey's test), than children with anxious symptoms (P=0.008 ; Tukey's test) or than control children (P=0.017 ; Tukey's test), respectively. Conclusion: Peripheral indices of 5-HT function are presumed to be associated with particular basic psychopathologic dimensions, but not with diagnostic entities. In line with this hypothesis, children with ADHD had similar platelet 5-HT concentration as control children matched for age. However, ADHD children with depressive symptoms had higher platelet 5-HT concentration than ADHD children with anxious, combination of depressive and anxious symptoms, without depressive or anxious symptoms or control children. Our data confirm the hypothesis that the increased platelet 5-HT concentration in depressive children with ADHD is a trait marker, predictive of depressive symptoms in ADHD.

Dosadašnja istraživanja neurobiološke podloge posttraumatskog stresnog poremećaja (PTSP)-a upućuju između ostaloga i na promjenu funkcije serotoninskog sustava i njegovih receptora. Serotoninski receptori tipa 2A (5-HT2A) se ubrajaju u drugu skupinu serotoninskih receptora. Nalaze se u mozgu na membrani postsinaptičkih neurona i periferno u stijenci krvnih žila i na membrani trombocita. 5-HT2A receptori sudjeluju u regulaciji odgovora na stres, ponašanja, tjelesne težine, spavanja, i tonusa krvnih žila. Opažena je promjena njihove aktivnosti u psihijatrijskih bolesnika, a mjesto su djelovanja atipičnih antipsihotika (olanzapin, risperidon, klozapin). Najnovija molekularna istraživanja su pronašla povezanost između polimorfizama gena za 5-HT2A receptore i psihičkih poremećaja (shizofrenije, depresije). Gen za 5-HT2A receptore je smješten na dugom kraku kromosoma 13 i sadrži tri eksona i dva introna. Najčešće istraživani polimorfizmi su -1438 A/G u promotorskom i T102C u kodirajućem dijelu 5-HT2A gena. Rezultati usporedbe kinetičkih karakteristika 5-HT2A receptora i T102C polimorfizma gena 5-HT2A receptore su pokazali povećani broj (funkciju) 5-HT2A receptora u mozgu i trombocitima zdravih osoba kod kojih je prisutan T alel, iako se u literaturi mogu naći i rezultati o nepovezanosti pojedinog alela i gustoće 5-HT2A receptora. Nedavno su objavljeni rezultati istraživanja -1438 A/G polimorfizma 5-HT2A gena u koreanskoj populaciji u kojima je pronađena povećana učestalost GG genotipa u žena ali ne i u muškaraca sa PTSP-om. Budući da nema podataka o T102C polimorfizmu 5-HT2A gena u PTSP-u, cilj istraživanja je bio odrediti T102C polimorfizam 5-HT2A gena u 92 veterana Domovinskog rata sa PTSP-om (DSM-IV kriteriji) i u 54 veterana Domovinskog rata koji nisu oboljeli od PTSP-a. Ispitanici su bili muškarci iste dobi i podjednakog borbenog iskustva, bez komorbidnih psihičkih poremećaja. Svim ispitanicima je izolirana DNK iz krvi. Uzorci DNK su podvrgnuti real time-PCR analizi, kako bi se utvrdila distribucija alela i genotipova T102C polimorfizma gena za 5-HT2A receptore. Rezultati su pokazali da je CC genotip prisutan u 32%, TC u 47%, a TT u 21% oboljelih od PTSP-a. U ratnih veterana bez PTSP-a 22% ispitanika su bili CC, a 21% TT homozigoti, a 57% su bili CT heterozigoti. Frekvencija pojavljivanja genotipova (CC, CT, TT) 5-HT2A gena u veterana bez PTSP-a nije se značajno (p=0, 36 ; hi2- test) razlikovala od one u oboljelih od PTSP-a. Opažena je granična (p=0, 09 ; hi2- test) razlika u distribuciji T i C alela 5-HT2A gena između ratnih veterana sa ili bez PTSP-a. T alel je bio prisutan u 38% oboljelih od PTSP-a i u 49% ratnih veterana bez PTSP-a. Distribucija genotipova i alela bila je podjednaka (p>0, 05 ; hi2- test) u oboljelih ratnih veterana sa ili bez suicidalnog ponašanja. Dobiveni rezultati pokazuju da je distribucija genotipova i alela gena 5-HT2A receptora u hrvatskih ispitanika u skladu s literaturnim podacima o distribuciji u populaciji europskog porijekla. Iako je ovim istraživanjem obuhvaćen mali broj ispitanika, rezultati upućuju da bi T alel 5-HT2A gena mogao predstavljati faktor rizika za pojavu PTSP-a u osoba izloženih traumi. Neophodno je daljnje istraživanje gena za proteine uključene u regulaciju metabolizma neurotransmitera i aktivnosti njihovih receptora u PTSP-u.

Istraživane su razlike u koncentraciji trombocitnog serotonina kod suicidalnih i nesuicidalnih bolesnika koji su bolovali od PTSP-a, depresije, drugih psihijatrijskih poremećaja.

Amyotrophic lateral sclerosis is a progressive and ultimately fatal neurodegenerative disease. The overlap between ALS and dementia is demonstrated by the presence of cognitive, behavioral dysfunction and change of personality in up to 50% of ALS patients. behavioral features are mostly due to changes in chatecholaminergic and serotonergic system.

Introduction: Posttraumatic stress disorder (PTSD) is a complex psychiatric and polygenetic disorder that occurs in some people exposed to extreme traumatic events. Literature data suggest that the alterations in serotonergic system and its receptors are involved in the aetiology and treatment of PTSD. Serotonergic receptors type 2A (5-HT2AR) are widely distributed in the brain and periphery. The association between T102C polymorphism of 5-HT2AR gene and personality traits including aggression and suicidality was reported. The aim of the present study was to determine a) the distribution of genotypes and alleles of the 5-HT2AR 102T/C SNP in healthy Croatian population and b) the association between 5-HT2AR gene polymorphism and vulnerability to PTSD in Croatian combat exposed war veterans. Subjects and Methods: The study included 264 war veterans (mean age &plusmn ; SD, 39.0&plusmn ; 9.8 years), with current chronic PTSD (SCID for DSM-IV), 89 combat exposed war veterans (age 38.1 &plusmn ; 4.2 years) without PTSD and 291 healthy male persons (age 41.5 &plusmn ; 12.1 years). PTSD diagnosis was evaluated with Structured Clinical Interview for DSM-IV. Genomic DNA was extracted from whole blood by a salting out procedure. The DNA samples were genotyped using ABI Prism 7000 Sequencing Detection System apparatus using Taqman-based allele-specific polymerase chain reaction assay. The chi-square (χ 2) test was applied to test the difference in genotype and allele frequencies of 5-HT2AR polymorphism between groups. Results: There was no significant deviation from the Hardy-Weinberg distribution for any group. Among healthy subjects CC, CT, TT genotype was found in 33.9%, 45.6% and 20.5% subjects respectively. CC genotype was found in 29.5%, CT in 43.2% and TT in 27.3% of war veterans with PTSD. Within war veterans without PTSD 38.2% carried CC, 46.1 CT and 15.7% TT genotype. 5-HT2AR genotype frequencies were similarly (χ 2=1.05, df=2, p=0.591) distributed between the two groups of war veterans A statistically significant (χ 2=5.06, df=1, p=0.024) difference was observed in alleles distribution between veterans with and without PTSD. C allele carriers were 51.1% and 61.2%, T allele carriers were 48.9% and 38.8% in war veterans with and without PTSD, respectively. Conclusions: Our results suggest that T allele of the 5-HT2AR 102T/C could be associated with the development of PTSD in subjects exposed to trauma.

Alzheimer disease (AD) is a neurodegenerative disease characterised by progressive cognitive decline, functional impairment, and psychotic symptoms. An enzyme catechol-O- methyltransferase (COMT) degrades dopamine and noradrenalin, and might be a risk factor for different psychiatric disorders, cognitive deficits and psychosis. COMT val158/met polymorphism results in guanine to adenine substitution at the exon 4 of the COMT gene (i.e. valine to methionine substitution). The presence of valine allele (high activity) is associated with up regulation of striatal dopamine activity and increased risk for psychosis in AD. Aim: The study evaluated the frequency of the COMT genotypes: GG (Val/Val), GA (Val/Met), and AA (Met/Met) in patients with psychotic and non-psychotic AD and in healthy controls. Methods: Probable AD fulfilling NINCDS-ADRDA criteria was diagnosed in 198 patients (DSM-IV-TR criteria): 63 with late and 135 with early onset (AD started after/before 65 years of age). Cognitive impairment was assessed using Mini Mental Status Examination (MMSE). In DNA samples COMT polymorphism was genotyped by TaqMan (Applied Biosystems) analysis. Results: The sample did not differ significantly (p>0.50) from Hardy-Weinberg equilibrium. Significant ( 2 =12.763 ; df=2 ; P = 0.002) differences in the frequency of the GG, GA or AA genotypes between 284 healthy control subjects (12%, 70% and 18%) and patients with AD (23%, 57% and 20%) ; or between healthy subjects and psychotic and non-psychotic patients with AD ( 2 =13.769 ; df=2 ; P = 0.008), or between healthy subjects and patients with early or late onset of AD ( 2 =13.315 ; df=2 ; P = 0.010) were found. MMSE scores did not differ significantly (F=2.103 ; df=2, 74 ; P = 0.129) between patients who had GG (16.58  6.4), GA (11.81  8.8), and AA (12.24  8.6) genotype. The distribution of the COMT genotypes did not differ significantly between 68 psychotic and 130 non-psychotic patients ( 2 =0.962 ; df=2 ; P = 0.618), or between patients with early or late onset of AD ( 2 =0.459 ; df=2 ; P = 0.795) were detected. Conclusion: Present results do not support the association of valine allele with psychosis, or methionine allele with better cognitive function in patients with AD. COMT polymorphism should be evaluated in larger groups with better cognitive characterisation.

Posttraumatic stress disorder (PTSD) is a serious psychiatric disorder. Biological basis of PTSD involves alterations in serotonin (5-HT), noradrenalin, and dopamine, and in genes controlling the activity of the corresponding proteins. Psychotic symptoms, which frequently occur in combat related PTSD, complicate the clinical picture and the treatment response. The aim of the study was to determine biomarkers and treatment response in male Croatian war veterans with current and chronic combat related PTSD (SCID and DSM-IV) with psychotic symptoms. Platelet biochemical markers (platelet monoamine oxidase (MAO-B) activity, and platelet 5-HT concentration), proposed to be related to particular symptoms or disorders, were found to be significantly higher in psychotic compared to non-psychotic veterans with PTSD. Plasma dopamine-beta-hydroxylase (DBH) activity did not differ between psychotic and non-psychotic PTSD veterans. The allele and genotype distribution of the catechol-O-methyl-transferase, brain derived neurotrophic factor, MAO-B, and DBH was similar, while the allele and genotype distribution of the 5-HT transporter gene-linked polymorphic region (5-HTTLPR) was significantly different between psychotic or non-psychotic veterans with PTSD. Our data show a biological distinction (in platelet 5-HT and platelet MAO-B, and different distribution of 5-HTT genotypes) in veterans with psychotic compared to non-psychotic PTSD. As some veterans with psychotic PTSD were refractory to usual treatment strategies, we studied the treatment response (reduction in the total and subscales scores in PTSD interview, Clinician-Administered PTSD Scale and Positive and Negative Syndrome Scale (PANSS) after 6 weeks monotherapy with typical (fluphenazine) or atypical (olanzapine, risperidone, quetiapine) antipsychotics. All antipsychotics reduced significantly the PTSD and psychotic symptoms (i.e. scores listed in trauma re-experiencing, avoidance, and hyper-arousal subscales of the CAPS, and total and subscales scores listed in positive, negative, general psychopathology, and supplementary items of the PANSS). Our results suggest that monotherapy with atypical antipsychotics improve clinical symptoms in treatment-resistant veterans with psychotic subtype of PTSD.

Posttraumatski stresni poremećaj (PTSP) je težak psihijatrijski poremećaj, praćen različitim komorbidnim poremećajima, često kroničnog tijeka, koji financijski opterećuje cijelo društvo i uzrokuje izrazitu patnju bolesnika i njihovih obitelji. Njegova neurobiološka podloga uključuje promjene u funkcioniranju različitih neurotransmitorskih i neuroendokrinih sustava. Genetske studije su potvrdile postojanje nasljednih čimbenika koji određuju sklonost razvoju PTSP-a, nakon što je osoba izložena traumatskom događaju. Za sada se zna da se PTSP češće javlja kod potomaka žrtava Holokausta te kod kambođanskih ratnih izbjeglica koji su bolovali od PTSP-a prema onim koji nisu bolovali od PTSP. Budući da je PTSP kompleksan poligenski poremećaj, potrebno je istražiti osim biološke i genetsku podlogu PTSP-a u svrhu boljeg razumijevanju nastanka, razvoja i liječenja PTSP-a. Monoaminooksidaza (MAO) je enzim koji se javlja u dva oblika (MAO-A i MAO-B) i čija je uloga oksidativna deaminacija dopamina, serotonina, noradrenalina i adrenalina. Trombocitna MAO ili MAO-B se koristi kao pokazatelj različitih poremećaja ponašanja i psihijatrijskih poremećaja. Najčešći polimorfizam gena za MAO-B javlja se u ponavljajućoj regiji njegovog 13. introna, i to kao promjena jedne baze (A ili G). S obzirom na smještaj polimorfizam ne utječe na strukturu gena, no radi utjecaja na efikasnost izrezivanja introna, polimorfizam može sudjelovati u regulaciji transkripcije gena za MAO-B, ili na stabilnost i/ili translaciju MAO-B mRNA. Neka su istraživanja uputila na povišenu aktivnost MAO-B kod osoba s G alelom. Budući da MAO katalizira deaminaciju neurotransmitora koji su promijenjeni u PTSP-u, cilj ovog istraživanja bio je odrediti aktivnost MAO-B u trombocitima i distribuciju MAO-B genotipova (A/G supstitucija u 13. intronu gena za MAO-B) kod oboljelih od PTSP-a i usporediti ih s vrijednostima u kontrolnoj skupini pripadnika zdrave populacije, a sve u svrhu stjecanja novih spoznaja o etiologiji PTSP-a. U 103 veterana Domovinskog rata s kroničnim PTSP-om dijagnosticiranom prema DSM-IV kriterijima, 41 veterana koji nisu razvili PTSP, i 242 kontrolna muška ispitanika određeni su aktivnost MAO-B i MAO-B intron 13 polimorfizam pomoću flurimetrijske i RT-PCR metode. Veterani s PTSP-om bili su podijeljeni u 28 ispitanika s prisutnim psihotičkim simptomima i 78 ispitanika bez psihotičkih simptoma (halucinacije ili deluzije na psihotičnom modulu strukturiranog psihijatrijskog intervjua, ili specifični poremećaji kod pregleda mentalnog statusa, i pomoću Skale pozitivnih i negativnih sindroma). Veterani s psihotičkim PTSP-om imali su značajno višu aktivnost trombocitne MAO-B nego veterani s ili bez PTSP-a ili zdravi ispitanici. Aktivnost MAO-B bila je snižena u trombocotima pušača prema nepušačima u svim skupinama. Pokazani su značajni učinci pušenja, dijagnoze i pušenja, ali ne genotipa, ili interakcije između genotipa, pušenja i dijagnoze, na aktivnost trombocitne MAO-B. Učestalost pojavljivanja MAO-B genotipa bila je slična među istraživanim skupinama. Polimorfizam na 13. intronu MAO-B gena nije bio funkcionalan, i nije utjecao na aktivnost MAO-B u trombocitima zdravih ispitanika ili veterana s ili bez PTSP-a, sa ili bez psihotičkih simptoma. Povišene vrijednosti MAO-B upućuju na zaključak da se psihotički oblik PTSP-a razlikuje od nepsihotičkog. Aktivnost MAO-B nadzire se vjerojatno pomoću drugih polimorfizama, koji su odgovorni za različite poremećaje ponašanja i psihičke poremećaje.

Introduction: Neurobiological basis of posttraumatic stress disorder (PTSD) involves the alternations in different neurotransmitter systems such as noradrenalin, dopamine and serotonin. Monoamine oxydase (MAO) is an enzyme responsible for the degradation of different endogenous and exogenous amines. Endogenous amines involve neurotransmitters (noradrenaline, dopamine and serotonin) and therefore MAO plays a central role in the metabolism of monoamine neurotransmitters. There are two isoforms of MAO, MAO-A and MAO-B. These subtypes are encoded by two different genes, placed near each other on X chromosome (region Xp11.23-11.4). In platelets MAO exists in MAO-B isoform, and it has been proposed to be a biomarker for different personality characteristics and psychiatric disorders. Platelet MAO or MAO-B activity is under influence of various factors, such as smoking, gender, age, ethnicity, some neurodegenerative diseases and lithium or haloperidol treatment. One of the factors assumed to influence platelet MAO activity might be a polymorphism of MAO-B gene on the polymorphic region of the intron 13. The molecular basis of this polymorphism is A/G substitution 36 bp upstream from the intron 13-exon 14 boundary. Aim of the study was to determine the distribution of the MAO-B genotypes in Croatian war veterans with PTSD, in war veterans who were exposed to the similar combat experience but did not develop PTSD, and in healthy control subjects. Methods: The study included medication-free male Caucasian subjects who did not have neurodegenerative diseases: 91 war veterans with PTSD, 36 war veterans without PTSD and 100 healthy control subjects. DNA was isolated from their blood samples, and the method used for genotyping was a real-time PCR using Taqman – based allele – specific polymerase chain reaction assay. Results: The results showed no differences in the distribution of A allele or G allele of the MAO-B gene between healthy control subjects, war veterans without PTSD, war veterans with PTSD with psychotic symptoms and war veterans with PTSD with non-psychotic symptoms. Discussion: Therefore, no association was found in the allele frequencies of the MAO-B genotype in PTSD. In agreement with our data, no significant association between the allele frequency and A/G polymorphism in intron 13 of the MAO-B gene was found in schizophrenia, schizophrenia with or without tardive dyskinesia, schizophrenia with aggressive behavior, migraine, Parkinson’ s disease, or depressed state. Since our data did not confirm the hypothesis that the appearance of A allele or G allele is associated with the etiology or development of PTSD, further studies should evaluate other polymorphisms, presumably related to MAO-A gene, to determine functional significance and associations with different traits or disease.

Neurobiološka podloga posttraumatskog stresnog poremećaja (PTSP) uključuje promjene u različitim neurotransmitorskim sustavima. Monoaminooksidaza tipa B (MAO-B) i katehol-o- metiltransferaza (COMT) su enzimi koji metaboliziraju noraadrenalin, dopamin i serotonin te tako utječu na njihovu funkciju i mogu poslužiti kao periferni biološki pokazatelji nekih psihijatrijskih poremećaja. Pretpostavlja se da na aktivnost ovih enzima, uz ostale čimbenike, utječu i polimorfizmi njihovih gena. Monoamionooksidaza postoji u dvije izoforme (tip A i tip B), a geni za oba podtipa nalaze se jedan uz drugog na kromosomu X (regija Xp11.23-11.4). Gen za COMT nalazi se na 22. kromosomu (regija q11.2), a budući da je ekspresija regulirana dvama različitim promotorima, gen kodira za dva proteina (COMT vezana za membranu i slobodna COMT). Hipoteza ovog rada je da postoji razlika u distribuciji genotipova MAO-B i COMT između skupina ispitanika oboljelih od PTSP i kontrolnih ispitanika. U ovom radu je kod tih skupina ispitanika određena distribucija genotipova MAO-B (supstitucija A/G u 13. intronu gena MAO- B) i COMT (supstitucija val158/108met). Korištena je DNA izolirana iz krvi ispitanika metodom isoljavanja. Ispitanici su podijeljeni u ratne veterane oboljele od PTSP-a (n=91), ratne veterane koji nisu oboljeli od PTSP (n=36) i zdrave ispitanike bez borbenog iskustva (n=100). Genotipizacija je izvršena pomoću 'real-time' lančane reakcije polimeraze koristeći Taqman alel-specificne PCR. Rezultati istraživanja nisu pokazali razlike u distribuciji odredenih genotipiva za MAO-B i COMT u ispitivanih skupina, upućujuci na pretpostavku da su ti genotipovi vezani za skupine simptoma ili poremećaje kognicije, a ne za dijagnostičke entitete.