Search

Cognitive deficits are a core feature of psychiatric disorders like schizophrenia and bipolar disorder. Evidence supports a genome-wide polygenic score (GPS) for educational attainment (GPSEDU) can be used to explain variability in cognitive performance. We aimed to identify different cognitive domains associated with GPSEDU in a transdiagnostic clinical cohort of chronic psychiatric patients with known cognitive deficits. Bipolar and schizophrenia patients from the PsyCourse cohort (N = 730; 43% female) were used. Likewise, we tested whether GPSs for schizophrenia (GPSSZ) and bipolar disorder (GPSBD) were associated with cognitive outcomes. GPSEDU explained 1.5% of variance in the backward verbal digit span, 1.9% in the number of correctly recalled words of the Verbal Learning and Memory Test, and 1.1% in crystallized intelligence. These effects were robust to the influences of treatment and diagnosis. No significant associations between GPSSZ or GPSBD with cognitive outcomes were found. Furthermore, these risk scores did not confound the effect of GPSEDU on cognitive outcomes. GPSEDU explains a small fraction of cognitive performance in adults with psychiatric disorders, specifically for domains related to linguistic learning and working memory. Investigating such a proxy-phenotype longitudinally, could give intriguing insight into the disease course, highlighting at what time genes play a more influential role on cognitive performance. Better understanding the origin of these deficits might help identify those patients at risk for lower levels of functioning and poor social outcomes. Polygenic estimates may in the future be part of predictive models for more personalized interventions.

In current diagnostic systems, schizophrenia and bipolar disorder are still conceptualized as distinct categorical entities. Recently, both clinical and genomic evidence have challenged this Kraepelinian dichotomy. There are only few longitudinal studies addressing potential overlaps between these conditions. Here, we present design and first results of the PsyCourse study (N = 891 individuals at baseline), an ongoing transdiagnostic study of the affective-to-psychotic continuum that combines longitudinal deep phenotyping and dimensional assessment of psychopathology with an extensive collection of biomaterial. To provide an initial characterization of the PsyCourse study sample, we compare two broad diagnostic groups defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) classification system, that is, predominantly affective (n = 367 individuals) versus predominantly psychotic disorders (n = 524 individuals). Depressive, manic, and psychotic symptoms as well as global functioning over time were contrasted using linear mixed models. Furthermore, we explored the effects of polygenic risk scores for schizophrenia on diagnostic group membership and addressed their effects on nonparticipation in follow-up visits. While phenotypic results confirmed expected differences in current psychotic symptoms and global functioning, both manic and depressive symptoms did not vary between both groups after correction for multiple testing. Polygenic risk scores for schizophrenia significantly explained part of the variability of diagnostic group. The PsyCourse study presents a unique resource to research the complex relationships of psychopathology and biology in severe mental disorders not confined to traditional diagnostic boundaries and is open for collaborations.

OBJECTIVES: Bipolar disorder (BD) with early disease onset is associated with an unfavorable clinical outcome and constitutes a clinically and biologically homogenous subgroup within the heterogeneous BD spectrum. Previous studies have found an accumulation of early age at onset (AAO) in BD families and have therefore hypothesized that there is a larger genetic contribution to the early-onset cases than to late onset BD. To investigate the genetic background of this subphenotype, we evaluated whether an increased polygenic burden of BD- and schizophrenia (SCZ)-associated risk variants is associated with an earlier AAO in BD patients. METHODS: A total of 1995 BD type 1 patients from the Consortium of Lithium Genetics (ConLiGen), PsyCourse and Bonn-Mannheim samples were genotyped and their BD and SCZ polygenic risk scores (PRSs) were calculated using the summary statistics of the Psychiatric Genomics Consortium as a training data set. AAO was either separated into onset groups of clinical interest (childhood and adolescence [≤18 years] vs adulthood [>18 years]) or considered as a continuous measure. The associations between BD- and SCZ-PRSs and AAO were evaluated with regression models. RESULTS: BD- and SCZ-PRSs were not significantly associated with age at disease onset. Results remained the same when analyses were stratified by site of recruitment. CONCLUSIONS: The current study is the largest conducted so far to investigate the association between the cumulative BD and SCZ polygenic risk and AAO in BD patients. The reported negative results suggest that such a polygenic influence, if there is any, is not large, and highlight the importance of conducting further, larger scale studies to obtain more information on the genetic architecture of this clinically relevant phenotype. peerReviewed

IMPORTANCE: Identifying psychosis subgroups could improve clinical and research precision. Research has focused on symptom subgroups, but there is a need to consider a broader clinical spectrum, disentangle illness trajectories, and investigate genetic associations. OBJECTIVE: To detect psychosis subgroups using data-driven methods and examine their illness courses over 1.5 years and polygenic scores for schizophrenia, bipolar disorder, major depression disorder, and educational achievement. DESIGN, SETTING, AND PARTICIPANTS: This ongoing multisite, naturalistic, longitudinal (6-month intervals) cohort study began in January 2012 across 18 sites. Data from a referred sample of 1223 individuals (765 in the discovery sample and 458 in the validation sample) with DSM-IV diagnoses of schizophrenia, bipolar affective disorder (I/II), schizoaffective disorder, schizophreniform disorder, and brief psychotic disorder were collected from secondary and tertiary care sites. Discovery data were extracted in September 2016 and analyzed from November 2016 to January 2018, and prospective validation data were extracted in October 2018 and analyzed from January to May 2019. MAIN OUTCOMES AND MEASURES: A clinical battery of 188 variables measuring demographic characteristics, clinical history, symptoms, functioning, and cognition was decomposed using nonnegative matrix factorization clustering. Subtype-specific illness courses were compared with mixed models and polygenic scores with analysis of covariance. Supervised learning was used to replicate results in validation data with the most reliably discriminative 45 variables. RESULTS: Of the 765 individuals in the discovery sample, 341 (44.6%) were women, and the mean (SD) age was 42.7 (12.9) years. Five subgroups were found and labeled as affective psychosis (n = 252), suicidal psychosis (n = 44), depressive psychosis (n = 131), high-functioning psychosis (n = 252), and severe psychosis (n = 86). Illness courses with significant quadratic interaction terms were found for psychosis symptoms (R(2) = 0.41; 95% CI, 0.38-0.44), depression symptoms (R(2) = 0.28; 95% CI, 0.25-0.32), global functioning (R(2) = 0.16; 95% CI, 0.14-0.20), and quality of life (R(2) = 0.20; 95% CI, 0.17-0.23). The depressive and severe psychosis subgroups exhibited the lowest functioning and quadratic illness courses with partial recovery followed by reoccurrence of severe illness. Differences were found for educational attainment polygenic scores (mean [SD] partial η(2) = 0.014 [0.003]) but not for diagnostic polygenic risk. Results were largely replicated in the validation cohort. CONCLUSIONS AND RELEVANCE: Psychosis subgroups were detected with distinctive clinical signatures and illness courses and specificity for a nondiagnostic genetic marker. New data-driven clinical approaches are important for future psychosis taxonomies. The findings suggest a need to consider short-term to medium-term service provision to restore functioning in patients stratified into the depressive and severe psychosis subgroups.

Background Religious delusions are a common symptom in patients experiencing psychosis, with varying prevalence rates of religious delusions across cultures and societies. To enhance our knowledge of this distinct psychotic feature, we investigated the mutually-adjusted association of genetic and environmental factors with occurrence of religious delusions. Methods We studied 262 adult German patients with schizophrenia or schizoaffective disorder. Association with lifetime occurrence of religious delusions was tested by multiple logistic regression for the following putative predictors: self-reported degree of religious activity, DSM-IV diagnosis, sex, age, education level, marital status, presence of acute delusion at the time of interview and an individual polygenic schizophrenia-risk score (SZ-PRS, available in 239 subjects). Results Of the 262 patients, 101 (39%) had experienced religious delusions. The risk of experiencing religious delusions was significantly increased in patients with strong religious activity compared to patients without religious affiliation (OR = 3.6, p = 0.010). Low or moderate religious activity had no significant effect. The same analysis including the SZ-PRS confirmed the effect of high religious activity on occurrence of religious delusions (OR = 4.1, p = 0.008). Additionally, the risk of experiencing religious delusions increased with higher SZ-PRS (OR 1.4, p = 0.020, using pT = 0.05 for SZ-PRS calculation). None of the other variables were significantly associated with lifetime occurrence of religious delusions. Conclusions Our results suggest that strong religious activity and high SZ-PRS are independent risk factors for the occurrence of religious delusions in schizophrenia and schizoaffective disorder.

Schizophrenia is a devastating disease that arises on the background of genetic predisposition and environmental risk factors, such as early life stress (ELS). In this study, we show that ELS-induced schizophrenia-like phenotypes in mice correlate with a widespread increase of histone-deacetylase 1 (Hdac1) expression that is linked to altered DNA methylation. Hdac1 overexpression in neurons of the medial prefrontal cortex, but not in the dorsal or ventral hippocampus, mimics schizophrenia-like phenotypes induced by ELS. Systemic administration of an HDAC inhibitor rescues the detrimental effects of ELS when applied after the manifestation of disease phenotypes. In addition to the hippocampus and prefrontal cortex, mice subjected to ELS exhibit increased Hdac1 expression in blood. Moreover, Hdac1 levels are increased in blood samples from patients with schizophrenia who had encountered ELS, compared with patients without ELS experience. Our data suggest that HDAC1 inhibition should be considered as a therapeutic approach to treat schizophrenia.

Prefrontal and anterior cingulate cortical regions are assumed to be involved in the pathophysiology of mood regulation. Reduced prefrontal and anterior cingulate function indicated by decreased N-acetyl-aspartate (NAA) levels in patients with bipolar disorder has been reported inconsistently. A positive correlation between lithium serum level and NAA concentrations has been found previously. The aim of this study was to re-investigate prefrontal and anterior cingulate neurochemistry in a sample of euthymic patients with bipolar I disorder.NAA, choline (Cho), creatine (Cr) and myo-inositol (Ins) in left dorsolateral prefrontal cortex and left anterior cingulate cortex were measured in 33 euthymic patients with bipolar I disorder and 29 healthy comparison subjects by using proton magnetic resonance spectroscopy ([(1)H]MRS).Metabolic ratios did not differ between patients with bipolar I disorder and comparison subjects in prefrontal and anterior cingulate cortex neither in the total sample nor in the pairwise matched sub-sample. We could not observe an association between lithium level and NAA ratios. Lithium treated patients demonstrated unchanged NAA or myo-inositol ratios compared to alternatively treated patients.In contrast to prior findings, we could not observe any metabolic alterations in euthymic patients with bipolar disorder.

Objective: Subcortical regions such as hippocampus, thalamus and ventral putamen are assumed to be involved in the pathophysiology of mood regulation. Disturbed hippocampal neuronal function indicated by reduced N-acetyl-aspartate (NAA) levels in bipolar patients was shown by several studies. Results in thalamus and putamen are inconsistent. Method: N-acetyl-aspartate, choline (Cho), creatine (Cr) and myo-inositol (Ins) were measured in left hippocampus, left thalamus and left putamen using proton magnetic resonance spectroscopy in 13 euthymic patients with bipolar I disorder and 13 pairwise matched healthy control subjects. Metabolic ratios NAA/Cr, NAA/Cho, Cho/Cr and Ins/Cr were calculated. Results: Patients with bipolar I disorder demonstrated significantly reduced NAA/Cr in the left hippocampus compared with healthy control subjects. No alterations were found in thalamus or putamen. Conclusion: We hypothesize that this NAA/Cr reduction might reflect neuronal dysfunction in the left hippocampus in patients with bipolar disorder.

The anterior limb of the internal capsule (ALIC), connecting cortical and subcortical structures, is involved in functional important circuits. To detect volumetric changes in ALIC, including the influence of genetic factors, a magnetic resonance imaging (MRI) study of families affected with schizophrenia was performed.The study sample comprised 22 family members with schizophrenia (FM-SZ), 34 family members without schizophrenia (FM-NSZ), and 43 control subjects. In addition to manual tracing of ALIC, subjects underwent proton magnetic resonance spectroscopy in the left prefrontal cortex, psychopathological rating, and neuropsychological assessment of frontal lobe function.Compared with controls, a significant reduction of right ALIC volume was seen in all family members (12%-16% reduction, p.01) and a reduction of left ALIC volume in FM-NSZ (10% reduction, p = .028) was also observed. Both groups of family members showed a bilateral reduction in maximal cross sectional area of the ALIC. FM-SZ performed significantly worse on neurocognitive measures (Subject Ordered Pointing Task [SOPT] and Wisconsin Card Sorting Test), and performance correlated negatively with the ALIC volume (SOPT, r = -.6, p = .03).A reduced volume of ALIC in affected families supports the hypothesis of disturbed frontothalamic connectivity in schizophrenia and demonstrates functional relevance by an association with reduced neurocognitive performance.

Background Gray matter reduction and ventricular enlargement belong to the best replicated findings in schizophrenia. Brain morphologic changes were also found in non-schizophrenic family members (FM). The intention of this study was to examine whether non-psychotic first-degree relatives reveal similar morphologic changes as schizophrenic patients and how state of genetic loading contribute to these abnormalities. Methods Forty-nine schizophrenic patients, 71 non-schizophrenic FM and 48 control subjects took part in this volumetric MRI study. All subjects were between 18 and 59 years old. Dependent variables were gray matter, white matter and total cerebrospinal fluid (CSF) volume, determined by SPM99 segmentation algorithm. As an important part of CSF lateral ventricle volume was determined manually by removing surrounding CSF areas. Results In schizophrenic patients compared to controls and non-schizophrenic FM total CSF volumes and lateral ventricles were increased. Gray and, to a lesser degree, white matter volumes were decreased as well. For CSF, gray and white matter there was no significant difference between uni- and multiple affected families. CSF correlated significantly negative with gray matter (r = −0.78) and, less intensive, with white matter (r = −0.40). There were negative correlations between gray and white matter volume as well (r = −0.26). These correlations were not significantly different between the diagnostic groups. Conclusion CSF enlargement and gray matter reductions in schizophrenic patients compared to controls and non-affected FM seem to be interdependent findings. However, this correlation is independent of the factor diagnosis and is therefore not specific for schizophrenia.

The brain serotonin-2A receptor (5-HT(2A)R) has been implicated in both the pathology of schizophrenia and the therapeutic action of atypical antipsychotics. However, little is known about the 5-HT(2A)R status before the onset of schizophrenia and before the exposure to antipsychotics. We used [18F] altanserin and positron emission tomography (PET) in a pilot study of 6 individuals suspected to be at elevated risk for schizophrenia and seven age-matched controls to test the hypothesis that regional 5-HT(2A)R binding is altered in the prodromal stages of schizophrenia. Distribution volume ratios (DVRs) as a proxy for 5-HT(2A)R availability were significantly reduced in prefrontal cortex regions of at-risk subjects, implicating early abnormalities of serotonergic neurotransmission that antecede the onset of schizophrenia.

Cerebrospinal fluid (CSF) space enlargement in schizophrenia is a prominent finding. This study was initiated to examine the influence of genetic loading, obstetric complications and premorbid adjustment on the extent of this enlargement. The sample of this MRI study consisted of 40 schizophrenic patients, 24 psychiatric and 40 healthy family members from 10 uniaffected and 19 multiple affected families with schizophrenia, such as 27 control subjects from non-affected families. The ventricle-to-brain-ratio (VBR), and the areas of the third ventricle, sylvian fissure, temporal horn and interhemispheric fissure at the slice where these structures reached their maximum were examined relatively to the corresponding total brain areas. The sum of CSF areas was calculated as a parameter for global atrophy. From MANCOVA adjusted for intervening variables the right VBR and the sum of CSF areas revealed significant differences between diagnostic groups. For these areas schizophrenic patients showed an increase compared to control subjects and family members with psychiatric disorder. Genetic loading influenced the interhemispheric fissure, enlarged in multiple affected compared to uniaffected families, and the temporal horn asymmetry, which was right sided (right > left) in control subjects and multiple affected families, but inverted in uniaffected families. Neonatal obstetric complications influenced only the size of the VBR, while premorbid adjustment predicted various CSF areas. In conclusion, schizophrenic subjects from multiple and uniaffected families showed a global atrophy, which was most pronounced in the VBR. Genetic loading seems to have an impact on frontal regions as the interhemispheric fissure and on the temporal horn.

The diacylglycerol kinase eta (DGKH) gene, first identified in a genome-wide association study, is one of the few replicated risk genes of bipolar affective disorder (BD). Following initial positive studies, it not only was found to be associated with BD but also implicated in the etiology of other psychiatric disorders featuring affective symptoms, rendering DGKH a cross-disorder risk gene. However, the (patho-)physiological role of the encoded enzyme is still elusive. In the present study, we investigated primarily the influence of a risk haplotype on amygdala volume in patients suffering from schizophrenia or BD as well as healthy controls and four single nucleotide polymorphisms conveying risk. There was a significant association of the DGKH risk haplotype with increased amygdala volume in BD, but not in schizophrenia or healthy controls. These findings add to the notion of a role of DGKH in the pathogenesis of BD.

Affective deficits are one common denominator of schizophrenia (SZ), bipolar disorder (BD) and obsessive compulsive disorder (OCD) with the amygdala indicated as one of the major structures involved in emotion regulation. Previous findings of differences in amygdala volume between healthy controls and patients with SZ, BD or OCD diverge with respect to the affected hemisphere, size and direction of the effect. Variability in the CACNA1C gene has been linked to BD, SZ as well as structural and functional variation in the amygdala in healthy people and patients with BD. We were interested to investigate whether amygdala volumes differ between hemispheres, diagnostic or genotype groups, and whether any interactive effects exist. We combined genotyping of SNP rs1006737 in CACNA1C with structural MRI measurements of relative gray matter (GM) amygdala volume in patients with SZ, BD or OCD as well as healthy controls (N Total = 72). The CACNA1C genotype showed a significant effect on relative GM amygdala volume in patients with SZ. There was a significant left versus right relative GM amygdala volume decrease in patients with SZ or BD. The effects of hemisphere and diagnosis (controls vs. patients with SZ) on relative GM amygdala volume were genotype specific. Our data suggest that the CACNA1C genotype may account for some heterogeneity in the effects of hemisphere and diagnosis on amygdala volume when comparing patients with SZ and controls and point to disturbed Ca(2+)-signaling as a plausible mechanism contributing to the pathology in patients with SZ.

The German Association for Psychiatry and Psychotherapy (DGPPN) has committed itself to establish a prospective national cohort of patients with major psychiatric disorders, the so-called DGPPN-Cohort. This project will enable the scientific exploitation of high-quality data and biomaterial from psychiatric patients for research. It will be set up using harmonised data sets and procedures for sample generation and guided by transparent rules for data access and data sharing regarding the central research database. While the main focus lies on biological research, it will be open to all kinds of scientific investigations, including epidemiological, clinical or health-service research.

Objective Suboptimal availability of circulating thyroid hormones may contribute to the high rate of treatment failures in bipolar disorder. This study tested the efficacy of adjunctive treatment with supraphysiologic doses of levothyroxine in patients with bipolar depression and the hypothesis that women would display a better outcome compared to men. Method The aims of this multicenter, 6-week, double-blind, randomized, placebo-controlled fixed-dose (300 μg/d) trial conducted from 2004 to 2009 were to assess efficacy and tolerability of levothyroxine adjunctive to continuing treatment with mood stabilizer and/or antidepressant medication for patients with bipolar I or II disorder, currently depressed (DSM-IV), and to investigate gender differences in treatment response. The primary efficacy variable was mean change in Hamilton Depression Rating Scale (HDRS) score. Results Of 74 patients enrolled in the study, 62 (35 with bipolar I; mean age = 44.9 years) were randomized. Mean change in HDRS score from randomization to week 6 was larger in the levothyroxine group compared to the placebo group, with a 2.7-point difference (decline of -7.8 [38.3%] vs -5.1 [25.5%]; last-observation-carried-forward analysis). The course of HDRS scores over time from randomization to week 6 was significantly different between groups at week 4 (P = .046) but not at the end of the placebo-controlled phase (P = .198). The secondary analysis of women (n = 32) revealed a significant difference between groups in mean change in HDRS score (-16.6% placebo vs -42.4% levothyroxine, P = .018). A mixed-effects model for repeated-measures analysis showed a significant between-group difference in HDRS score (6.8, P = .012) for women. High thyroid-stimulating hormone levels, indicating suboptimal levels of circulating thyroid hormones, were predictive for positive treatment outcome in women treated with levothyroxine in a linear regression model (F3 = 3.47; P = .05). Discussion This trial demonstrated that patients treated with levothyroxine did numerically better than those treated with placebo; however, the study failed to detect a statistically significant difference between the 2 groups in the primary outcome measure due to a high placebo response rate. Previous findings that women show better improvement in depression scores with levothyroxine compared to men were confirmed. Trial registration ClinicalTrials.gov identifier: NCT01528839.

DISC1 (Disrupted-In-Schizophrenia 1), one of the top candidate genes for schizophrenia, has been associated with a range of major mental illnesses over the last two decades. DISC1 is crucially involved in neurodevelopmental processes of the human brain. Several haplotypes and single nucleotide polymorphisms of DISC1 have been associated with changes of grey matter volumes in brain regions known to be altered in schizophrenia and other psychiatric disorders. The aim of the present study was to investigate the effects of two single nucleotide polymorphisms (SNPs) of DISC1 on grey matter volumes in human subjects using voxel-based morphometry (VBM). 114/113 participating subjects (psychiatric patients and healthy controls) were genotyped with respect to two at-risk SNPs of DISC1, rs6675281 and rs821616. All participants underwent structural magnetic resonance imaging (MRI). MRI data was statistically analyzed using voxel-based morphometry. We found significant alterations of grey matter volumes in prefrontal and temporal brain regions in association with rs6675281 and rs821616. These effects of DISC1 polymorphisms on brain morphology provide further support for an involvement of DISC1 in the neurobiology of major psychiatric disorders such as schizophrenia.

Several neuroimaging studies have reported structural brain differences in bipolar disorder using automated methods. While these studies have several advantages over those using region of interest techniques, no study has yet estimated a summary effect size or tested for between-study heterogeneity. We sought to address this issue using meta-analytic techniques applied for the first time in bipolar disorder at the level of the individual voxel.A systematic review identified 16 voxel-based morphometry (VBM) studies comparing individuals with bipolar disorder with unaffected controls, of which eight were included in the meta-analysis. In order to take account of heterogeneity, summary effect sizes were computed using a random-effects model with appropriate correction for multiple testing.Compared with controls, subjects with bipolar disorder had reduced grey matter in a single cluster encompassing the right ventral prefrontal cortex, insula, temporal cortex, and claustrum. Study heterogeneity was widespread throughout the brain; though the significant cluster of grey matter reduction remained once these extraneous voxels had been removed. We found no evidence of publication bias (Eggers p = 0.63).Bipolar disorder is consistently associated with reductions in right prefrontal and temporal lobe grey matter. Reductions elsewhere may be obscured by clinical and methodological heterogeneity.

The brain-derived neurotrophic factor (BDNF) is a key regulator of synaptic plasticity and has been suggested to be involved in the pathophysiology and pathogenesis of psychotic disorders, with particular emphasis on dysfunctions of the hippocampus. The aim of the present study was to replicate and to extend prior findings of BDNF val66met genotype effects on hippocampal volume and N-acetyl aspartate (NAA) levels. Hundred and fifty-eight caucasians (66 schizophrenic, 45 bipolar, and 47 healthy subjects; 105 subjects underwent MRI and 103 MRS scanning) participated in the study and were genotyped with regard to the val66met polymorphism (rs6265) of the BDNF gene. Hippocampal volumes were determined using structural magnetic resonance imaging (MRI), and measures of biochemical markers were taken using proton magnetic resonance spectroscopy ((1)H-MRS) in the hippocampus and other brain regions. Verbal memory was assessed as a behavioral index of hippocampal function. BDNF genotype did not impact hippocampal volumes. Significant genotype effects were found on metabolic markers specifically in the left hippocampus. In particular, homozygous carriers of the met-allele exhibited significantly lower NAA/Cre and (Glu + Gln)/Cre metabolic ratios compared with val/val homozygotes, independently of psychiatric diagnoses. BDNF genotype had a numerical, but nonsignificant effect on verbal memory performance. These findings provide first in vivo evidence for an effect of the functional BDNF val66met polymorphism on the glutamate system in human hippocampus. peerReviewed

Impairments in memory and executive function are key components of schizophrenia. These disturbances have been linked to several subcortical and cortical networks. For example, anatomical and functional changes in the hippocampus have been linked to deficits in these cognitive domains. However, the association between hippocampal morphometry, neurochemistry and function is controversial. Therefore, we aimed to investigate the relationship between hippocampal anomalies and their functional relevance.Fifty-seven first-episode schizophrenia patients (FE-SZ) and 61 healthy control subjects (HC) participated in this study. Hippocampal volumes were investigated using structural magnetic resonance imaging (sMRI) and hippocampal neurochemistry was determined using proton magnetic resonance spectroscopy (1H MRS). Verbal memory was used as a hippocampus-dependent cognitive task whereas working memory and cognitive flexibility assessed frontal lobe function.FE-SZ presented smaller volumes of the left hippocampus, with a significant correlation between left hippocampal volume and verbal memory performance (immediate recall). There was also an inverse correlation between neurochemical ratios (NAA/Cho and Cho/Cr) and verbal memory (delayed recognition). Tests of cognitive flexibility and working memory were not correlated with MRI and 1H MRS values. Compared to HC, FE-SZ demonstrated reduced performance in all of the assessed neurocognitive domains.These results point to a relationship between verbal memory and hippocampal integrity in schizophrenia patients which might be independent from deficits in other memory domains. Disturbed verbal memory functions in FE-SZ might be linked specifically to hippocampal function.

Structural magnetic resonance imaging (MRI) studies reveal evidence for brain abnormalities in obsessive–compulsive disorder (OCD), for instance, reduction of gray matter volume in the prefrontal cortex. Disturbances of gyrification in the prefrontal cortex have been described several times in schizophrenia pointing to a neurodevelopmental etiology, while gyrification has not been studied so far in OCD patients. In 26 OCD patients and 38 healthy control subjects MR-imaging was performed. Prefrontal cortical folding (gyrification) was measured bilaterally by an automated version of the automated-gyrification index (A-GI), a ratio reflecting the extent of folding, from the slice containing the inner genu of the corpus callosum up to the frontal pole. Analysis of covariance (ANCOVA, independent factor diagnosis, covariates age, duration of education) demonstrated that compared with control subjects, patients with OCD displayed a significantly reduced A-GI in the left hemisphere (p = 0.021) and a trend for a decreased A-GI in the right hemisphere (p = 0.076). Significant correlations between prefrontal lobe volume and A-GI were only observed in controls, but not in OCD patients. In conclusion, prefrontal hypogyrification in OCD patients may be a structural correlate of the impairment in executive function of this patient group and may point to a neurodevelopmental origin of this disease. peerReviewed

Usher J, Menzel P, Schneider-Axmann T, Kemmer C, Reith W, Falkai P, Gruber O, Scherk H. Increased right amygdala volume in lithium-treated patients with bipolar I disorder. Objective: The amygdala plays a major role in processing emotional stimuli. Fourteen studies using structural magnetic resonance imaging (MRI) have examined the amygdala volume in paediatric and adult patients with bipolar disorder (BD) compared with healthy controls (HC) and reported inconsistent findings. Lithium has been found to increase grey matter volume, and first evidence points towards an effect on regional brain volume such as the amygdala. Method: We examined the amygdala volume of euthymic patients with BD treated with lithium (n = 15), without lithium (n = 24) and HC (n = 41) using structural MRI. Results: Patients treated with lithium exhibited in comparison to HC a larger right absolute (+17.9%, P = 0.015) and relative (+18%, P = 0.017) amygdala volume. There was no significant difference in amygdala volume between patients without lithium treatment and HC. Conclusion: Lithium appears to have a sustained effect on a central core region of emotional processing and should therefore be considered in studies examining BD.

Objective: Meta-analytic findings support the hypothesis of specific neurocognitive deficits for bipolar patients in the domains of attention, processing speed, memory and executive functions. This study aims to show neurocognitive impairment in euthymic patients with bipolar I disorder compared with healthy controls while detailing the impact of medication side-effects or illness characteristics on neuropsychological test performance. Method: Forty euthymic patients with bipolar I disorder were compared with 40 healthy controls in a cross-sectional design. Clinical features and neuropsychological measures of IQ, psychomotor speed, verbal fluency, learning and memory, executive functions and attention were assessed. Results: Patients without antipsychotic drug use did not differ significantly from healthy controls in any neuropsychological measure. Yet patients treated with antipsychotics showed significant underperformance in the domains of semantic fluency, verbal learning and recognition memory as well as executive functions related to planning abilities, even when clinical features were controlled for. Conclusion: The impact of antipsychotic medication needs to be further clarified for euthymic bipolar patients and should be considered when neuropsychological test performance is interpreted.

Cognitive dysfunction is a common finding in schizophrenia. Nevertheless the specific pattern of neuropsychological impairment in schizophrenia compared to other severe mental illnesses has not been intensively studied. Twenty-four patients with schizophrenia belonging to different stages of the disease (11 first-episode patients, 13 patients with multiple episodes), 18 patients with bipolar disorder and 23 healthy control subjects underwent standardized neuropsychological assessment. Statistical analysis of covariance (ANCOVA) demonstrated that, compared to control subjects, patients with schizophrenia performed significantly worse in the trail-making test (P = 0.012), verbal fluency (category letter, P = 0.004), verbal learning/memory (P = 0.005), and the Wisconsin Card Sorting Test (WCST) (P = 0.004 for administered trials; P = 0.025 for perseverative responses, T value) indicating significant deficits in attention and psychomotor performance, and in particular in verbal working memory and cognitive flexibility for schizophrenic patients. A significant difference between schizophrenic and bipolar patients was found only in the WCST. Schizophrenic patients made significantly more perseverative responses (P = 0.002, ANCOVA), indicating a more pronounced and specific deficit in cognitive flexibility and frontally based executive function. In conclusion, these results may suggest a cognitive endophenotype in schizophrenia and underline the role of the prefrontal cortex in schizophrenic pathophysiology.

The SNAP-25 gene is an integral part of the vesicle docking and fusion machinery that controls neurotransmitter release. Several post mortem studies revealed a reduction of SNAP-25 protein in the hippocampus of patients with schizophrenia and bipolar disorder (BD). Thirty-eight patients with schizophrenia, BD or obsessive-compulsive disorder and 17 healthy controls participated in the study. Proton magnetic resonance spectroscopy in left hippocampus was performed in each individual. Three single nucleotide polymorphisms (SNP) of the SNAP-25 gene were genotyped. Individuals with the homozygous CC genotype of the DdeI SNP presented a significantly higher ratio of N-acetyl-aspartate (NAA)/choline-containing compounds (Cho) in the left hippocampus compared to the group of individuals with the homozygous TT genotype. The SNAP-25 genotype may modulate synaptic plasticity and neurogenesis in the left hippocampus, and altered NAA/Cho ratio may be an indicator for this genetic modulation of neuronal function in the hippocampus. peerReviewed

Background Structural brain imaging is assumed to be a key method to elucidate the underlying neuropathology of bipolar disorder. However, magnetic resonance imaging studies using region of interest analysis and voxel-based morphometry (VBM) revealed quite inconsistent findings. Hence, there is no clear evidence so far for core regions of cortical or subcortical structural abnormalities in bipolar disorder. The aim of this study was to investigate grey and white matter volumes in a large sample of patients with bipolar I disorder. Methods Thirty-five patients with bipolar I disorder and 32 healthy controls matched with respect to gender, handedness and education participated in the study. MRI scanning was performed and an optimized VBM analysis was conducted. Results We could not observe any significant differences of grey or white matter volumes between patients with bipolar disorder and healthy control subjects. Additional analyses did not reveal significant correlations between grey or white matter volume with number of manic or depressive episodes, duration of illness, existence of psychotic symptoms, and treatment with lithium or antipsychotics. Conclusions With this VBM study we were not able to identify core regions of structural abnormalities in bipolar disorder.

Dopaminergic activity in the brain is modulated by the dopamine transporter (DAT). Several lines of evidence suggest that a variable number of tandem repeats (VNTR) polymorphism of the DAT1 gene (SLC6A3) influences its gene expression. The aim of this study was to determine whether the DAT1VNTR polymorphism alters the metabolic ratios NAA/Cho, NAA/Cr, Cho/Cr and Ins/Cr in the left dorsolateral prefrontal cortex, anterior cingulate cortex, and putamen in healthy subjects and psychiatric patients irrespective of clinical diagnosis.Sixty-four individuals (30 patients with bipolar disorder, 18 patients with obsessive-compulsive disorder, and 16 healthy subjects) participated in the study. The 3'-UTR VNTR polymorphism of DAT1 (SLC6A3) gene was genotyped in all individuals. (1)H-MRS was performed in the above-mentioned brain regions.The individuals with the homozygous DAT1 10-repeat genotype presented significantly higher ratios of NAA/Cho and NAA/Cr in the left putamen compared to the group of individuals with the 9/9-repeat or 9/10-repeat genotype.The VNTR polymorphism of the DAT1-gene modulates NAA/Cho and NAA/Cr in the left putamen independent of psychiatric diagnosis status. These results suggest an association of DAT1 VNTR polymorphism, dopaminergic activity, and neuronal function in putamen.

We used proton magnetic resonance spectroscopy ( 1 H MRS) to examine biochemical characteristics of the brain tissue in subjects at risk for schizophrenia. Nineteen participants fulfilling research criteria for an early ( n = 10) or a late ( n = 9) at-risk syndrome, 21 patients with full disease according to DSM IV and 31 healthy control subjects were included in the study. Single-voxel 1 H MRS was performed in the left frontal lobe, the anterior cingulate gyrus and the left superior temporal lobe. Subjects were followed longitudinally to detect conversion to schizophrenia. We observed a significant reduction of the metabolic ratios NAA/Cr and NAA/Cho in the left frontal lobe and of NAA/Cr in the anterior cingulate gyrus in both at-risk groups and in the schizophrenic patients compared with healthy controls. Those at-risk subjects, who converted to schizophrenia within the observation period, had a higher Cho/Cr and a lower NAA/Cho ratio in the anterior cingulate gyrus compared with non-converters. NAA/Cr did not differ between converters and non-converters. Six at-risk subjects were taking antidepressants, two were taking antipsychotics. There was no difference in any metabolic ratio in any region between at-risk subjects with and without medication. We conclude that the reduction of the neuronal marker NAA in the left prefrontal lobe and the anterior cingulate gyrus may represent a vulnerability indicator for schizophrenia in at-risk subjects, while elevated Cho in the anterior cingulate gyrus may be a predictor for conversion from the prodromal state to the full disease.

Various polymorphisms of the X-chromosomal monoamine oxidase A (MAO-A) gene were investigated for association with affective disorders. However, none of the studied variants could consistently be associated with either major depressive or bipolar affective disorder. Recently, a positive association between panic disorder and a novel functional repeat polymorphism in the MAO-A gene promoter, with the longer alleles being more active, was reported. Since monoaminergic neurotransmission is supposed to play an important role in affective disorders, we investigated a potential association of this polymorphism with major depressive illness in a sample of 146 unrelated patients of German descent and a control group of 101 individuals with a negative life history for affective disorders. Similarly to the recent findings in panic disorder, we observed a significantly increased frequency of genotypes containing only long alleles in female patients with recurrent major depression in comparison with age- and sex-matched controls. Thus, our data suggest that an excess of high-activity MAO-A gene promoter alleles resulting in an elevated MAO-A activity is a risk factor for major depressive disorder in females. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:801-803, 2000.

Context Hippocampal volume is lower than expected in patients with schizophrenia; however, whether this represents a fixed deficit is uncertain. Exercise is a stimulus to hippocampal plasticity. Objective To determine whether hippocampal volume would increase with exercise in humans and whether this effect would be related to improved aerobic fitness. Design Randomized controlled study. Setting Patients attending a day hospital program or an outpatient clinic. Patients or Other Participants Male patients with chronic schizophrenia and matched healthy subjects. Interventions Aerobic exercise training (cycling) and playing table football (control group) for a period of 3 months. Main Outcome Measures Magnetic resonance imaging of the hippocampus. Secondary outcome measures were magnetic resonance spectroscopy, neuropsychological (Rey Auditory Verbal Learning Test, Corsi block-tapping test), and clinical (Positive and Negative Syndrome Scale) features. Results Following exercise training, relative hippocampal volume increased significantly in patients (12%) and healthy subjects (16%), with no change in the nonexercise group of patients (−1%). Changes in hippocampal volume in the exercise group were correlated with improvements in aerobic fitness measured by change in maximum oxygen consumption ( r = 0.71; P = .003). In the schizophrenia exercise group (but not the controls), change in hippocampal volume was associated with a 35% increase in the N -acetylaspartate to creatine ratio in the hippocampus. Finally, improvement in test scores for short-term memory in the combined exercise and nonexercise schizophrenia group was correlated with change in hippocampal volume ( r = 0.51; P Conclusion These results indicate that in both healthy subjects and patients with schizophrenia hippocampal volume is plastic in response to aerobic exercise.

There are several hypotheses on functional neuronal networks that modulate mood states and which might form the neuroanatomical basis of bipolar disorder. The thalamus has been reported to be a key structure within the circuits that modulate mood states and might thus play an important role within the aetiology of the bipolar affective disorder. Nevertheless, structural brain imaging studies on the thalamus volume of bipolar patients have shown heterogeneous results. Using structural MRI scanning, we compared the thalamus volume of 41 euthymic bipolar patients to the thalamus volume of 41 well-matched healthy controls. Taking the concomitant medication as a co-variable within the patient group, the analysis of variance revealed a significantly smaller relative volume of the right thalamus in patients not treated with lithium when compared with healthy controls. In contrast, there are no significant differences concerning the thalamus volume between all euthymic bipolar patients and healthy controls. The study only shows findings of a transverse section. No longitudinal analysis was performed. More detailed information on patients’ pharmacological histories could not be obtained. In conclusion, this result may be interpreted as an indication of the impact of the thalamus in the pathogenesis of the bipolar I disorder and emphasises the need for further longitudinal studies in bipolar patients with special attention paid to the concomitant medication, in particular to the role of lithium. peerReviewed

Background Functional imaging studies in healthy individuals revealed an association between 5-HTTLPR genotype and neuronal activity in the amygdala. The aim of this study was firstly to investigate a possible overall impact of the 5-HTTLPR on amygdala volume in patients with bipolar disorder and healthy individuals and secondly to test a diagnosis specific influence of the 5-HTTLPR on amygdala volume. Methods We performed a region of interest analysis of amygdala volume in 37 patients with bipolar I disorder and 37 healthy control subjects. The 5-HTTLPR genotype of each proband was determined and the subjects were separated according to 5-HTTLPR genotype and for statistical analyses the groups SS and SL were combined and compared with the group LL. Results This study shows that carriers of the short allele (SL or SS) of the 5-HTTLPR polymorphism exhibit a relatively increased volume of the right amygdala compared to homozygous L-allele carriers irrespective of diagnosis status. However, further analyses with the factors genotype and diagnosis were not able to reproduce this result. Conclusions The present findings are consistent with the view that the 5-HTTLPR polymorphism might modulate neuronal size or number in the amygdala. It would be worthwhile investigating the relationship between serotonin transporter function and amygdala function and volume in further studies.

DTNBP1 is one of the most established susceptibility genes for schizophrenia, and hippocampal volume reduction is one of the major neuropathological findings in this severe disorder. Consistent with these findings, the encoded protein dysbindin-1 has been shown to be diminished in glutamatergic hippocampal neurons in schizophrenic patients. The aim of this study was to investigate the effects of two single nucleotide polymorphisms of DTNBP1 on grey matter volumes in human subjects using voxel-based morphometry. Seventy-two subjects were included and genotyped with respect to two single nucleotide polymorphisms of DTNBP1 (rs2619522 and rs1018381). All participants underwent structural magnetic resonance imaging (MRI). MRI data were preprocessed and statistically analysed using standard procedures as implemented in SPM5 (Statistical Parametric Mapping), in particular the voxel-based morphometry (VBM) toolbox. We found significant effects of the DTNBP1 SNP rs2619522 bilaterally in the hippocampus as well as in the anterior middle frontal gyrus and the intraparietal cortex. Carriers of the G allele showed significantly higher grey matter volumes in these brain regions than T/T homozygotes. Compatible with previous findings on a role of dysbindin in hippocampal functions as well as in major psychoses, the present study provides first direct in vivo evidence that the DTNBP1 SNP rs2619522 is associated with variation of grey matter volumes bilaterally in the hippocampus.