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Schizophrenia (SZ) is a severe mental illness with high heritability and complex etiology. Mounting evidence from neuroimaging has implicated disrupted brain network connectivity in the pathophysiology. However, previous findings are inconsistent, likely due to a combination of methodological and clinical variability and relatively small sample sizes. Few studies have used a data-driven approach for characterizing pathological interactions between regions in the whole brain and evaluated the generalizability across independent samples. To overcome this issue, we collected resting-state functional magnetic resonance imaging data from 3 independent samples (1 from Norway and 2 from Sweden) consisting of 182 persons with a SZ spectrum diagnosis and 348 healthy controls. We used a whole-brain data-driven definition of network nodes and regularized partial correlations to evaluate and compare putatively direct brain network node interactions between groups. The clinical utility of the functional connectivity features and the generalizability of effects across samples were evaluated by training and testing multivariate classifiers in the independent samples using machine learning. Univariate analyses revealed 14 network edges with consistent reductions in functional connectivity encompassing frontal, somatomotor, visual, auditory, and subcortical brain nodes in patients with SZ. We found a high overall accuracy in classifying patients and controls (up to 80%) using independent training and test samples, strongly supporting the generalizability of connectivity alterations across different scanners and heterogeneous samples. Overall, our findings demonstrate robust reductions in functional connectivity in SZ spectrum disorders, indicating disrupted information flow in sensory, subcortical, and frontal brain regions. [ABSTRACT FROM AUTHOR]

Background: Patients with schizophrenia show increased brain and cerebrospinal fluid (CSF) concentrations of the endogenous N-methyl-D-aspartate receptor antagonist kynurenic acid (KYNA). This compound is an end-metabolite of the kynurenine pathway, and its formation indirectly depends on the activity of kynurenine 3-monooxygenase (KMO), the enzyme converting kynurenine to 3-hydroxykynurenine. Methods: We analyzed the association between KMO gene polymorphisms and CSF concentrations of KYNA in patients with schizophrenia and healthy controls. Fifteen single nucleotide polymorphisms (SNPs) were selected covering KMO and were analyzed in UNPHASED. Results: We included 17 patients with schizophrenia and 33 controls in our study. We found an association between a KMO SNP (rs1053230), encoding an amino acid change of potential importance for substrate interaction, and CSF concentrations of KYNA. Limitations: Given the limited sample size, the results are tentative until replication. Conclusion: Our results suggest that the nonsynonymous KMO SNP rs1053230 influences CSF concentrations of KYNA. [ABSTRACT FROM AUTHOR]

Objective: To investigate suicide ideation and behavior as risk factors for suicide in schizophrenia during varying time periods., Method: Cases were 84 patients who died by suicide within 5 years from diagnosis in a source population of patients discharged for the first time from psychiatric hospitals in Stockholm County, Sweden, with a schizophrenia spectrum diagnosis. One control was individually matched with each suicide case. Data were retrieved from clinical records in a blind fashion. Thoughts of death, thoughts of suicide, suicide plan, and suicide attempt during varying time periods were investigated as risk factors for subsequent completed suicide., Results: In adjusted analyses, thoughts of suicide, suicide plan, and suicide attempt were significantly associated with subsequent completed suicide in the following year. The highest suicide risk was found within a year following suicide attempt (adjusted OR 9.9, 95% confidence interval 2.5-39.0). The association between suicide ideation and behavior and subsequent suicide declined over time., Conclusions: Several types of suicide ideation and behavior were associated with suicide, and the association was stronger for suicidal behavior. The clinical significance of suicidal communication appears highest during the following month or/and year. Many suicides occurred without recorded short-term suicidal communication., (© 2018 The American Association of Suicidology.)

Objective: Patients treated with antipsychotic drugs often receive concomitant psychotropic compounds. Few studies address this issue from a lifetime perspective. Here, an analysis is presented of the prescription pattern of such concomitant medication from the first contact with psychiatry until the last written note in the case history documents, in patients with a diagnosis of psychotic illness., Methods: A retrospective descriptive analysis of all case history data of 66 patients diagnosed with schizophrenia or schizophrenia-like psychotic disorders., Results: Benzodiazepines and benzodiazepine-related anxiolytic drugs had been prescribed to 95% of the patients, other anxiolytics, sedatives or hypnotic drugs to 61%, anti-parkinsonism drugs to 86%, and antidepressants to 56% of the patients. However, lifetime doses were small and most of the time patients had no concomitant medication. The prescribed lifetime dose of anti-parkinsonism drugs was associated with that of prescribed first-generation but not second-generation antipsychotics., Conclusions: Most psychosis patients are sometimes treated with concomitant drugs but mainly over short periods. Lifetime concomitant add-on medication at the individual patient level is variable and complex but not extensive., (Copyright © 2011 John Wiley & Sons, Ltd.)

Introduction: Patients with schizophrenia have higher rates of mortality than the general population. Lower concentrations of the cerebrospinal fluid (CSF) monoamine metabolites homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) have been associated with suicidal, aggressive and impulsive behavior. Mortality has been suggested as a measure of impulsivity and a relationship between early death and lower concentrations of CSF monoamine metabolites has been reported but the studies are few with short periods of follow-up and small numbers., Aim: The objective of this study was to investigate a relationship between early death and concentrations of CSF 5-HIAA and HVA., Methods: Three hundred and eighty-five inpatients with schizophrenia spectrum psychosis were lumbar punctured in a standardized manner and followed for a median of 26 years. Patients were searched to identify those who had died. Causes of death were obtained from the Causes of Death Register., Results: During the time of follow-up, 97 patients died. Schizophrenia spectrum psychosis patients died at an earlier age from both natural and unnatural causes of death. No significant associations were found between CSF 5-HIAA and HVA concentrations and non-suicidal death. Attempted suicide was not a risk factor for non-suicidal death at younger age., Conclusion: Patients with schizophrenia spectrum psychosis die at an earlier age from both natural and unnatural causes of death. Attempted suicide is not a risk factor for non-suicidal death at younger age. Low concentrations of CSF HVA and 5-HIAA were not a risk factor for non-suicidal death at younger age in schizophrenia spectrum psychosis.

Background: Earlier studies of patients with schizophrenia have investigated suicide risk in relation to specific psychiatric symptoms, but it remains to be better understood how suicide risk relates to the diagnostic profile in these patients., Methods: We identified all patients with a first clinical ICD-diagnosis of schizophrenia, schizophreniform or schizoaffective disorder in Stockholm County between 1984 and 2000. Patients who died by suicide within five years from diagnosis were defined as cases (n=84) and were individually matched with a similar number of living controls from the same population. Sociodemographic and clinical variables were retrieved from hospital records through a blind process. DSM-IV lifetime diagnoses for cases and controls were derived using the OPCRIT algorithm., Results: A schizophrenia spectrum diagnosis (i.e. schizophrenia, schizophreniform or schizoaffective disorder) was assigned by OPCRIT to 50% of the suicide cases and 62% of the controls. Criteria for schizophrenia were met by 41% of the cases and 51% of the controls; for schizoaffective disorder by 8% of the cases and 10% of the controls; for other psychosis by 23% of the cases and 25% of the controls; and for mood disorder by 26% of the cases and 12% of the controls. Using the schizophrenia diagnosis as a reference, suicide risk was significantly higher in patients meeting criteria for a mood disorder diagnosis with an adjusted odds ratio of 3.3 (95% CI 1.2-9.0)., Conclusion: In patients with a clinical schizophrenia spectrum diagnosis, a DSM-IV mood disorder diagnosis increases the suicide risk more than three-fold., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Previous reports regarding risk factors for suicide in schizophrenia have been inconclusive. We performed a matched case-control study of in-patient-treated schizophrenia patients in order to assess the suicide risk associated with socioeconomic, demographic, and psychiatric factors. The cases were 84 patients who died by suicide within five years after diagnosis in a cohort of all patients discharged for the first time from psychiatric hospitals in Stockholm County, Sweden, with a diagnosis of schizophrenia, schizophreniform disorder or schizoaffective disorder between the years 1984 and 2000. One control was individually and randomly matched with each case from the same cohort by date (+/-1 year) and age (+/-5 years) at index diagnosis. Data were retrieved from clinical records of the case-control pairs in a blind fashion. Of the suicides, 54% were men and 46% were women. In multivariate analyses, higher educational attainment (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.03-8.0), age >or=30 years at onset of symptoms (OR 4.8, CI 1.1-21.2), and a history of a suicide attempt requiring non-psychiatric medical treatment (OR 5.0, CI 1.6-15.4) were found to be significantly associated with an increased suicide risk. Gender did not significantly affect the suicide risk, nor did a history of self-discharge, compulsory in-patient treatment, substance-use disorder or a family history of mental disorders or suicide. In schizophrenia, certain suicide risk factors may differ from those in the general population. Clinical suicide risk assessment for schizophrenia patients should be performed taking this into account.

Morphological abnormalities of the cerebral cortex have been reported in a number of MRI-studies in schizophrenia. Uncertainty remains regarding cause, mechanism and progression of the alterations. It has been suggested that antipsychotic medication reduces total gray matter volumes, but results are inconsistent. In the present study differences in regional cortical thickness between 96 patients with a DSM-IV diagnosis of schizophrenia (n=81) or schizoaffective disorder (n=15) and 107 healthy subjects (mean age 42 years, range 17-57 years) were investigated using MRI and computer image analysis. Cortical thickness was estimated as the shortest distance between the gray/white matter border and the pial surface at numerous points across the entire cortical mantle. The influence of age and antipsychotic medication on variation in global and regional cortical thickness was explored. Thinner cortex among patients than controls was found in prefrontal and temporal regions of both hemispheres, while parietal and occipital regions were relatively spared. Some hemispheric specificity was noted, as regions of the prefrontal cortex were more affected in the right hemisphere, and regions of the temporal cortex in the left hemisphere. No significant interaction effect of age and diagnostic group on variation in cortical thickness was demonstrated. Among patients, dose or type of antipsychotic medication did not affect variation in cortical thickness. The results from this hitherto largest study on the topic show that prefrontal and temporal cortical thinning in patients with schizophrenia compared to controls is as pronounced in older as in younger subjects. The lack of significant influence from antipsychotic medication supports that regional cortical thinning is an inherent feature of the neurobiological disease process in schizophrenia.

Polymorphisms in the brain-derived neurotrophic factor (BDNF) gene have been suggested to be associated with schizophrenia. In a replication attempt, Swedish patients with schizophrenia (n=187) and control subjects (n=275) were assessed for four BDNF gene polymorphisms. There were no significantly different allele, genotype or haplotype frequencies between cases or controls. Neither were there any differences when schizophrenic patients were sub-divided with regard to a number of different clinical variables, although a small group of psychotic patients with prominent affective features displayed higher frequencies of the less common alleles of the Val66Met and 11757 G/C polymorphisms compared to controls. The present Swedish results do not verify previous associations between putative functional BDNF gene polymorphisms and schizophrenia. However, when combined with previous studies meta-analyses indicated that the BDNF 270 T-allele and the Val66Met homozygous state were associated with the disorder. Thus, the BDNF gene may confer susceptibility to schizophrenia. Additional studies are warranted to shed further light on this possibility.

We aimed to estimate the value of structured interviews, medical records and Swedish register diagnoses for assessing lifetime diagnosis of patients with schizophrenia. Psychiatric records and diagnostic interviews of 143 Swedish patients diagnosed by their treating physician with schizophrenia and related disorders were scrutinized. Based on record analysis only, or a combined record and interview analysis, DSM-IV diagnoses were obtained by the OPCRIT algorithm. Independent of the OPCRIT algorithm, a standard research DSM-IV diagnosis, based on both record and interview analysis, was given by the research psychiatrist. Concordance rates for the different psychosis diagnoses were calculated. DSM-IV diagnoses based on records only, showed a good to excellent agreement with diagnoses based on records and interviews. Swedish register diagnoses displayed generally poor agreement with the research diagnoses. Nevertheless, 94% of subjects sometimes registered with a diagnosis of schizophrenic psychoses (i.e. schizophrenia, schizoaffective psychosis or schizophreniform disorder) displayed a standard research DSM-IV diagnosis of these disorders. For patients in long-term treatment for schizophrenia in Sweden, psychiatric record reviews should be optimal, cost effective and sufficient for assessment of lifetime research diagnoses of schizophrenia. For these patients a research interview adds little new information. The results further indicate that a Swedish register diagnosis of schizophrenic psychoses has a high positive predictive power to a standard research DSM-IV diagnosis of the disorders. It is concluded that for future Swedish large-scale genetic studies focusing on a broad definition of schizophrenia, it would be sufficient to rely on the Swedish register diagnoses of schizophrenic psychosis.

The gender diagnosticity (GD) approach of Lippa (1995) was used to evaluate the relationship of within-sex differences in psychological masculinity-femininity to a genetic characteristic, the length of a repeated CAG sequence in the X-linked androgen receptor (AR) gene. Previously assessed adult samples in Australia and Sweden were used for this purpose. A weak relationship (correlations in the range .11 to .14) was obtained in both countries. Additional data from adolescent twins from Australia (12-, 14-, 16-year-olds) did not confirm such a relationship at those ages, especially for males. The fact that this sample consisted of twins permitted two kinds of within-pair comparisons: (1) Did the dizygotic twin who had the longer AR sequence have the higher GD score? (2) Was one twin's GD score more highly correlated with the other twin's AR score in MZ than in DZ pairs? The answer in both cases was negative. Clarification of these relationships will require large samples and measurements at additional ages.

Objective: Disturbances in catecholamine transmission have been implicated in schizophrenia. Dopamine beta-hydroxylase catalyses the conversion of dopamine to norepinephrine in noradrenergic cells. We attempted to investigate a putative functional promoter polymorphism in the dopamine beta-hydroxylase gene (DBH) for association with schizophrenia., Methods: Unrelated schizophrenic patients (n=155) and control subjects (n=436) were analysed with regard to the DBH -1021 C/T variant., Results: No significant allele or genotype differences were found., Conclusions: The present results do not support a major involvement of the DBH gene in schizophrenia in the Swedish population investigated.

We have previously identified mutations in exon three in NURR1 (NR4A2) in two patients with schizophrenia (SZ) and one patient with bipolar disease with psychotic symptoms. In the present study we analyzed the promoter region of NURR1 and identified five polymorphic sites: three were found to be in strong linkage disequilibrium with a previously identified polymorphic site in the sixth intron. One polymorphism of this haplotype and the two other independent polymorphisms were investigated for their possible association with SZ and Parkinson's disease (PD) by comparing their frequencies in a Swedish material consisting of 134 subjects with SZ and 207 matched controls and 108 subjects with PD and 125 matched controls. Exon 1 was also investigated in our Parkinson and control material but no variances were found. The distributions of the two most informative polymorphisms in the promoter were investigated in an American material as well consisting of 141 subjects with SZ and 139 matched controls. Furthermore, the identified markers were screened for association with putative endophenotypes of SZ in the Swedish material. The distribution of sequence variants among the Swedish controls matched for SZ was investigated with regard to personality. No significant genotype or allelic association of the three sequence variants with SZ or PD was found. Several comparisons regarding endophenotypes or personality indicated association at the 5% confidence level, although correction for multiple testing rendered none of these findings significant. We conclude that the identified polymorphic sites in the human NURR1 are unlikely to be involved in conferring susceptibility for SZ or PD in our patient material., (Copyright 2003 Wiley-Liss, Inc.)

Studies in Sweden and Australia have examined the relationship between number of CAG repeats in the androgen receptor gene and psychological traits - three Masculinity-Femininity (M-F) measures in Australia, and the Karolinska Scales of Personality (KSP) in Sweden. The present study derived M-F scales from the KSP items, and scales corresponding to several KSP scales from the items of the inventories used in Australia, to permit cross-validation of the Australian results in the Swedish sample, and vice versa. The derivation of scales was facilitated by the fact that items from both inventories had been used with a large twin sample in the US. Correlation of the derived scales with androgen receptor gene CAG-repeat scores for women in the Australian and Swedish samples failed to provide clear evidence of replication of either set of original correlations in the other sample, although there were a few hints of consistency. It was concluded that if the number of CAG repeats on this gene is related to psychological traits at all, the relationship is a weak one.

An association has been reported between a dopamine D(2) receptor gene (DRD2) Ser311Cys variant and schizophrenia. In a replication attempt, Swedish patients with schizophrenia (n = 173) and control subjects (n = 236) were assessed for the DRD2 Ser311Cys variant. Schizophrenic patients displayed higher Cys311 allele frequencies than control subjects (4.0 vs. 0.8%, chi(2) = 9.49, df = 1, P = 0.002; odds ratio (OR) 4.93, 95% confidence interval (95% CI) 1.61-15.12). The association was detected only in men. The results were supported by a meta-analysis of all published case-control studies comprising a total of 9,152 subjects (chi(2) = 11.37, df = 1, P < 0.001; OR 1.43, 95% CI 1.16-1.78). The present results support the involvement of the DRD2 gene in the pathogenesis of schizophrenia., (Copyright 2003 Wiley-Liss, Inc.)

Background: Personality traits have shown considerable heritable components. Striatal dopamine D(2) receptor density, as determined by positron-emission tomography, has been associated with detached personality, as assessed by the Karolinska Scales of Personality. A putative functional promoter polymorphism in the dopamine D(2) receptor gene (DRD2), -141C ins/del, has been associated with dopamine D(2) receptor density., Methods: In this study healthy subjects (n = 235) who filled in at least one of several personality questionnaires (Karolinska Scales of Personality, Swedish Universities Scales of Personality, Health-relevant Five-factor Personality Inventory, and Temperament and Character Inventory) were analyzed with regard to the DRD2 -141C ins/del variant., Results: There was an association (p =.001) between the DRD2 -141C ins/del variant and Karolinska Scales of Personality Detachment scale, indicating higher scores in subjects with the -141C del variant. There were also associations between the DRD2 -141C ins/del variant and a number of Karolinska Scales of Personality and Swedish Universities Scales of Personality Neuroticism-related scales, but of these only Swedish Universities Scales of Personality Lack of Assertiveness scale (p =.001) survived correction for multiple testing., Conclusions: These results add further support for the involvement of dopamine D(2) receptor in certain personality traits. The results should be treated with caution until replicated.

Background: Recently, linkage disequilibrium mapping of the major histocompatibility complex region on the short arm of human chromosome 6 suggested that the NOTCH4 locus is highly associated with schizophrenia., Objectives and Methods: We analysed two polymorphisms in this gene in Swedish schizophrenic patients ( =74) and control subjects ( =135). The NOTCH4 variants were also analysed in schizophrenic patients with regard to subdiagnosis, age at first hospitalization, abuse/dependence of alcohol, solvents, or drugs, previous suicide attempts, extrapyramidal symptoms, treatment with anticholinergic drugs, and response to anti-psychotic drug treatment. Control subjects were scrutinized with regard to personality, another partially heritable trait suggested being of importance in schizophrenia. In addition, two intermediate endophenotypes suggested being of importance in schizophrenia, dopamine D(2) receptor density in striatum and monoamine metabolites in cerebrospinal fluid, respectively, were investigated with regard to the two NOTCH4 variants., Results: There was no significant association between the patients and the controls for the two investigated polymorphisms neither for the parameters analysed in the schizophrenia material. The NOTCH4 SNP2 variant, an A-->G substitution, was associated with the Karolinska Scales of Personality Irritability scale. The NOTCH4 (CTG)(n) variant was associated with the revised NEO personality inventory Extraversion and Activity (E4) scales. However, after correction for multiple testing, no difference remained significant. The results for the endophenotypes and the polymorphisms were non-significant., Conclusions: The present study does not support that the investigated NOTCH4 variants have a major influence on susceptibility to schizophrenia or related neurobiological traits.

Genetic components are involved in the aetiology of schizophrenia. Activating Protein 2 (AP-2) transcription factors are essential for neural gene expression and neural development. Transcription factor AP-2beta has also been connected with monoaminergic genes and monoamine levels in various brain regions. Thus, the AP-2beta gene is a suitable candidate taking both the neurodevelopmental and dopamine hypotheses of schizophrenia into account. We investigated 135 schizophrenic patients and 382 control subjects with regard to an intronic AP-2beta variant without evidence of any association. We conclude that the investigated AP-2beta variant is not of major importance to schizophrenia in the investigated Swedish population., (Copyright 2002 Elsevier Science Ltd.)