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Abstract: Objectives: Although sleep disorders have been reported to affect more than half of adults with attention-deficit/hyperactivity disorder (ADHD), the association between sleep and ADHD is poorly understood. The aims of our study were to investigate sleep-related variables in adults with ADHD and to assess if any differences exist between ADHD of the predominantly inattentive (ADHD-I) and combined (ADHD-C) subtypes. Methods: We used the Epworth sleepiness scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), and the fatigue severity scale (FSS) to collect data on daytime sleepiness, sleep quality, and fatigue in 126 subjects (45 ADHD-I and 81 ADHD-C subjects). Results: Approximately 85% of subjects reported excessive daytime sleepiness or poor sleep quality. The most common sleep concerns were initial insomnia, interrupted sleep, and feeling too hot. When examining ADHD subtype differences, ADHD-I subtypes reported poorer sleep quality and more fatigue than ADHD-C subtypes. Partial correlation analyses revealed that interrelationships between sleep quality, daytime sleepiness, and fatigue differ between ADHD subtypes; in ADHD-I subtypes fatigue was associated with sleep quality, while in the ADHD-C subtypes fatigue was associated with both sleep quality and daytime sleepiness. There also appears to be a subtype×gender interaction that affects the perception of fatigue, as subjective fatigue was markedly higher in ADHD-I women than in ADHD-C women. Conclusion: Altogether our data indicate that the interplay of variables associated with daytime function and sleep varies between ADHD subtypes. This finding may have considerable relevance in the management and pathophysiologic understanding of ADHD, and thus lead to tailored treatments for ADHD subtypes. [Copyright &y& Elsevier]

Adults with ADHD smoke cigarettes at a higher rate than normal subjects. Nicotine has been shown to significantly improve clinical ADHD symptoms as measured by the Clinical Global Impression scale (CGI) as well as by measures of attention, vigour and arousal in ADHD subjects. In this study we hypothesized that the allele 113bp in D15S1360 marker at CHRNA7 and the 2 bp deletion allele at CHRFAM7A are associated with increased smoking in a sample of 90 DSM-IV patients affected by Adult ADHD. Temperament and Character Inventory (TCI) scores were included as covariates in the analysis to distinguish the contribution of personality traits from the contribution of the nicotinic genes under investigation. Smoking status was determined from the medical history questionnaire, and there were 35 current smokers and 55 non-smokers. Single marker associations and the CHRNA7-CHRFAM7A interaction were calculated by logistic regression, considering the 113 bp and the −2 bp deletion in a dominant model. No association of these genes with smoking was observed. Similarly, no significant interaction between the genes was observed in the logistic model. However, Persistence score of the TCI was significantly associated with smoking status. Further investigation on the hypothesis of the molecular interaction between CHRNA7 and CHRFAM7A genes is warranted. [ABSTRACT FROM AUTHOR]

To examine the unity and diversity of inattention and hyperactivity/impulsivity symptom domains of Attention-Deficit/Hyperactivity Disorder (ADHD) in a clinical sample of adolescents with ADHD. Parents and adolescents were administered a semi-structured diagnostic interview, the Schedule for Affective Disorders and Schizophrenia for School-Age Children — Present and Lifetime Version (K-SADS-PL), to assess adolescent ADHD. Data from 201 parent interviews and 189 adolescent interviews were examined. Four potential factor structures for the 18 ADHD symptoms were tested using confirmatory factor analysis: two models with correlated factors and two bifactor models. A bifactor model with two specific factors best accounted for adolescent symptoms, according to both parent and adolescents’ reports. Replication of these findings from behavioral rating scales completed for this sample by parents and teachers indicates that the findings are not method– or informant-specific. The results suggest that there is an important unitary component to ADHD symptoms and separable dimensional traits of Inattention and Hyperactivity/Impulsivity. [ABSTRACT FROM AUTHOR]

Performance-based measures and ratings of executive functions were examined in a sample of adolescents with attention deficit/hyperactivity disorder (ADHD) and comparison controls. Performance-based measures of executive function included inhibition, working memory, set shifting, and planning, and ratings of these same executive functions were completed by parents and teachers. Adolescents with ADHD demonstrated lower executive function performance than controls and displayed elevated ratings on the executive function ratings by parents and teachers. Significant associations were obtained between the performance-based measures and the parent and teacher ratings, but each measure was not uniquely associated with its respective scale on the rating scales. When performance-based measures and ratings were examined as predictors of ADHD status, the parent and teacher ratings entered as significant predictors of ADHD status. Further commonality analyses indicated that performance-based measures accounted for little unique variance in predicting ADHD status and also displayed little overlap with the behavioral ratings. These findings highlight the diagnostic utility of behavioral ratings of executive function in predicting ADHD status; however, behavioral ratings should not be assumed to be a proxy for performance on measures of executive function in clinical practice. [ABSTRACT FROM AUTHOR]

Background: To investigate the effects of methylphenidate (MPH) on components of working memory (WM) in attention-deficit hyperactivity disorder (ADHD) and determine the responsiveness of WM measures to MPH. Methods: Participants were a clinical sample of 50 children and adolescents with ADHD, aged 6 to 16 years old, who participated in an acute randomized, double-blind, placebo-controlled, crossover trial with single challenges of three MPH doses. Four components of WM were investigated, which varied in processing demands (storage versus manipulation of information) and modality (auditory-verbal; visual-spatial), each of which was indexed by a minimum of two separate measures. Results: MPH improved the ability to store visual-spatial information irrespective of instrument used, but had no effects on the storage of auditory-verbal information. By contrast, MPH enhanced the ability to manipulate both auditory-verbal and visual-spatial information, although effects were instrument specific in both cases. Conclusions: MPH effects on WM are selective: they vary as a function of WM component and measurement. [ABSTRACT FROM AUTHOR]

Background: The objective of the current study was to examine performance and correlates of performance on a decision-making card task involving risky choices (Iowa Gambling Task) in adolescents with ADHD and comparison controls. Forty-four participants with ADHD and 34 controls were administered measures of estimated intellectual ability, working memory, and the card task. Also, behavioural ratings were obtained from parents and teachers. Results: Adolescents with ADHD scored lower on the measures of intellectual ability, working memory, and made less advantageous selections on the card task compared to controls. Performance on measures of intellectual ability and working memory were unrelated to card task performance in both the ADHD and control samples. Parent ratings of hyperactivity/impulsivity were significantly associated with card task performance in the adolescents with ADHD, but not in controls. Conclusion: These findings demonstrate impaired decision-making in adolescents with ADHD, and the separability of motivational and executive function processes, supporting current dual pathway models of ADHD. [ABSTRACT FROM AUTHOR]

Reading comprehension is a very complex task that requires different cognitive processes and reading abilities over the life span. There are fewer studies of reading comprehension relative to investigations of word reading abilities. Reading comprehension difficulties, however, have been identified in two common and frequently overlapping childhood disorders: reading disability (RD) and attention-deficit/hyperactivity disorder (ADHD). The nature of reading comprehension difficulties in these groups remains unclear. The performance of four groups of adolescents (RD, ADHD, comorbid ADHD and RD, and normal controls) was compared on reading comprehension tasks as well as on reading rate and accuracy tasks. Adolescents with RD showed difficulties across most reading tasks, although their comprehension scores were average. Adolescents with ADHD exhibited adequate single word reading abilities. Subtle difficulties were observed, however, on measures of text reading rate and accuracy as well as on silent reading comprehension, but scores remained in the average range. The comorbid group demonstrated similar difficulties to the RD group on word reading accuracy and on reading rate but experienced problems on only silent reading comprehension. Implications for reading interventions are outlined, as well as the clinical relevance for diagnosis. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Numerous lines of evidence have shown that attention deficit hyperactivity disorder (ADHD) is a highly heritable disorder, whether it is considered as a category or a dimension. We tested for an association between the dopamine transporter gene (DAT1) and ADHD considering the disorder as categorical as well as a continuous trait. Genotypes for the DAT1 variable number of tandem repeat (VNTR) alleles, along with Brown Attention Deficit Disorder Scale (BADDS) and Wender Utah Rating Scale (WURS) scores were available for 152 adult ADHD patients. In 72 of these patients DNAs from at least one parent were accessible to perform a family-based analysis (FBAT). The mean quantitative trait values of the whole sample of singleton patients were compared among the specific genotype groups using ANOVA. The family-based analysis did not reveal any association between DAT1 alleles and ADHD either when it was considered as a dichotomous trait (Z = 0.16, p = .86) or as a continuous trait (Wender Scale Z = −1.67, p = .09; Brown ADD Scale Z = 0.28, p = .77). No significant differences were detected in the mean symptom scores among the specific genotype groups. The results from our study do not support a major role for the DAT1 VNTR alleles in our sample of adult ADHD. In view of several positive reports in child ADHD, more work is required to elucidate the potential role of the DAT1 VNTR as a risk factor in ADHD. [Copyright &y& Elsevier]

Convincing data support the hypothesis that genetic factors are involved in the etiology of attention-deficit hyperactivity disorder (ADHD). Various lines of evidence have shown that the dopamine system plays a crucial role in the pathophysiology of ADHD. The dopamine D3 receptor gene (DRD3) represents a promising candidate to examine in ADHD. Animal studies have shown that DRD3 mRNA is highly expressed in the ventral striatum suggesting an involvement of this receptor in the control of motor behaviour. Manipulation of DRD3 in rodents has led to a mouse model with nonfunctional D3 receptors that displays hyperactive behaviour in various environmental conditions. Furthermore, administration of 7-OH-DPAT, a dopaminergic agonist that binds preferentially to D3 receptors exerts an inhibitory effect on locomotor activity while D3 antagonists induce hyperactivity. Among various polymorphisms described for DRD3, the BalI polymorphism is most interesting because it codes for an aminoacid substitution in the N-terminus of the receptor. The receptor products of the two alleles (Ser/Gly) exhibit differential affinity for dopamine. To determine if DRD3 Ser9/Gly is involved in the susceptibility to ADHD we genotyped 39 adults with ADHD and their respective parents (trios). Adult ADHD represents a promising phenotype for studying the genetic component of the disorder. In fact, a recent family study has shown that relatives of adult ADHD patients have a higher rate of ADHD compared to relatives of children with ADHD suggesting a stronger genetic component for the adult version. The results of genotyping in the 39 trios analyzed with the transmission disequilibrium test showed no excess of transmission for DRD3 MscI/BalI alleles (χ2=0.360; df=1; P=0.54). This result, although from a relatively small sample, indicates that it is unlikely that DRD3 is playing a major role in the etiology of ADHD in our sample. [Copyright &y& Elsevier]

Children with attention-deficit hyperactivity disorder (ADHD) do not typically outgrow this condition in adolescence, which is a challenging period of development. Management of ADHD in adolescence requires specific accommodations. These include providing adolescents with as much control over treatment as possible, so that they perceive treatment to be widening their autonomy rather than limiting it. Wherever possible, medication needs to be long-acting to facilitate compliance and to minimize problems with rebound misbehaviour and moodiness. Comorbid psychiatric symptoms and syndromes need to be evaluated carefully both pre- and posttreatment. Ongoing psychoeducation and support can help to restructure the demands that an adolescent with ADHD faces at home and school so that they are more manageable. With active treatment it may be possible to prevent the serious morbidity associated with ADHD during this period and to lay a foundation for adulthood. [ABSTRACT FROM AUTHOR]

Purpose:The purpose of this study is to examine the relationships among self-reported screening measures of attention deficit hyperactivity disorder (ADHD), other psychiatric problems, and driving-related outcomes in a provincially representative sample of adults 18 years and older living in the province of Ontario, Canada. Methods:The study examined the results of the Centre for Addictions and Mental Health (CAMH) Ontario Monitor, an ongoing repeated cross-sectional telephone survey of Ontario adults over a 2-year period. Measures included ADHD measures (Adult ADHD Self-Report Scale-V1.1 [ASRS-V1.1], previous ADHD diagnosis, ADHD medication use); psychiatric distress measures (General Health Questionnaire [GHQ12], use of pain, anxiety, and depression medication); antisocial behavior measure (The Antisocial Personality Disorder Scale from the Mini-International Neuropsychiatric Interview [APD]); substance use and abuse measures (alcohol, cannabis, and cocaine), Alcohol Use Disorders Identification Test (AUDIT), Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), driving-related outcomes (driving after drinking, driving after cannabis use, street racing, collisions in past year), and sociodemographics (gender, age, vehicle-kilometers traveled). Results:A total of 4,014 Ontario residents were sampled, of which 3,485 reported having a valid driver's license. Overall, 3.22% screened positive for ADHD symptoms on the ASRS-V1.1 screening tool. A greater percentage of those who screened positive were younger, reported previous ADHD diagnosis and medication use, distress, antisocial behavior, anti-anxiety and antidepressant medication use, substance use, and social problems compared to those who screened negative. However, there were no statistically significant differences between those who screened positive or negative for ADHD symptoms on self-reported driving after having 2 or more drinks in the previous hour; within an hour of using cannabis, marijuana, or hash; or in a street race or collision involvement as a driver in the past year. When a sequential regression was conducted to predict self-reported collisions, younger age and higher weekly kilometers driven showed higher odds of collision involvement, and the odds ratio for cannabis use ever approached statistical significance. Discussion:This study is the first population-based study of a representative sample of adults 18 years and older living in Ontario, Canada. These results showed no relationship between the ADHD screen and collision when age, sex, and kilometers driven are controlled for. However, these analyses are based on self-report screeners and not psychiatric diagnoses and a limited sample of ADHD respondents. Thus, these results should be interpreted with caution. [ABSTRACT FROM PUBLISHER]

Abstract: Increasing evidence suggests that symptoms of attention deficit hyperactivity disorder (ADHD) could persist into adult life in a substantial proportion of cases. The aim of the present study was to investigate the impact of (1) adverse events, (2) personality traits and (3) genetic variants chosen on the basis of previous findings and (4) their possible interactions on adult ADHD severity. One hundred and ten individuals diagnosed with adult ADHD were evaluated for occurrence of adverse events in childhood and adulthood, and personality traits by the Temperament and Character Inventory (TCI). Common polymorphisms within a set of nine important candidate genes (SLC6A3, DBH, DRD4, DRD5, HTR2A, CHRNA7, BDNF, PRKG1 and TAAR9) were genotyped for each subject. Life events, personality traits and genetic variations were analyzed in relationship to severity of current symptoms, according to the Brown Attention Deficit Disorder Scale (BADDS). Genetic variations were not significantly associated with severity of ADHD symptoms. Life stressors displayed only a minor effect as compared to personality traits. Indeed, symptoms’ severity was significantly correlated with the temperamental trait of Harm avoidance and the character trait of Self directedness. The results of the present work are in line with previous evidence of a significant correlation between some personality traits and adult ADHD. However, several limitations such as the small sample size and the exclusion of patients with other severe comorbid psychiatric disorders could have influenced the significance of present findings. [Copyright &y& Elsevier]

Abstract: Several lines of evidence from neuroimaging, pharmacology and genetics support the involvement of the dopaminergic system in the etiology of Attention Deficit Hyperactivity Disorder (ADHD). Previous candidate gene studies have investigated the association between a dinucleotide (CA)n repeat polymorphism, located 18.5kb from the start codon of the DRD5 gene, and ADHD. Association between the 148bp allele and ADHD has been reported in some studies, however replication of the finding has not been consistent. We tested for an association between the (CA)n repeat and adult ADHD in a sample comprised of 119 families with adult ADHD probands and 88 unrelated adult ADHD cases with a corresponding number of controls matched for age, ethnicity and sex. In the family sample we found a non-significant trend for association between the 148bp allele and ADHD (Z =1.91, p =0.055). An excess of non-transmissions was detected for the 150 and 152bp alleles (Z =−2.26, p =0.023; Z =−2.20, p =0.028). Quantitative analysis performed using the Brown Attention Deficit Disorder Scale (BADDS) showed association between the 150bp allele and lower total score (p =0.011), and lower effort (p =0.008), activation (p =0.008) and attention (p =0.01) cluster scores. We did not replicate association findings in the case–control group, likely due to the lack of statistical power of this sample. Our findings add to the literature suggesting DRD5 (CA)n repeat has a modest effect in modulating susceptibility to adult ADHD but further studies are required. [Copyright &y& Elsevier]