Lipid Alteration Signature in the Blood Plasma of Individuals With Schizophrenia, Depression, and Bipolar Disorder

Importance

No clinically applicable diagnostic test exists for severe mental disorders. Lipids harbor potential as disease markers.

Objective

To define a reproducible profile of lipid alterations in the blood plasma of patients with schizophrenia (SCZ) independent of demographic and environmental variables and to investigate its specificity in association with other psychiatric disorders, ie, major depressive disorder (MDD) and bipolar disorder (BPD).

Design, Setting, and Participants

This was a multicohort case-control diagnostic analysis involving plasma samples from psychiatric patients and control individuals collected between July 17, 2009, and May 18, 2018. Study participants were recruited as consecutive and volunteer samples at multiple inpatient and outpatient mental health hospitals in Western Europe (Germany and Austria [DE-AT]), China (CN), and Russia (RU). Individuals with DSM-IV or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnoses of SCZ, MDD, BPD, or a first psychotic episode, as well as age- and sex-matched healthy controls without a mental health-related diagnosis were included in the study. Samples and data were analyzed from January 2018 to September 2020.

Main Outcomes and Measures

Plasma lipidome composition was assessed using liquid chromatography coupled with untargeted mass spectrometry.

Results

Blood lipid levels were assessed in 980 individuals (mean [SD] age, 36 [13] years; 510 male individuals [52%]) diagnosed with SCZ, BPD, MDD, or those with a first psychotic episode and in 572 controls (mean [SD] age, 34 [13] years; 323 male individuals [56%]). A total of 77 lipids were found to be significantly altered between those with SCZ (n = 436) and controls (n = 478) in all 3 sample cohorts. Alterations were consistent between cohorts (CN and RU: [Pearson correlation] r = 0.75; DE-AT and CN: r = 0.78; DE-AT and RU: r = 0.82; P < 10-38). A lipid-based predictive model separated patients with SCZ from controls with high diagnostic ability (area under the receiver operating characteristic curve = 0.86-0.95). Lipidome alterations in BPD and MDD, assessed in 184 and 256 individuals, respectively, were found to be similar to those of SCZ (BPD: r = 0.89; MDD: r = 0.92; P < 10-79). Assessment of detected alterations in individuals with a first psychotic episode, as well as patients with SCZ not receiving medication, demonstrated only limited association with medication restricted to particular lipids.

Conclusions and Relevance

In this study, SCZ was accompanied by a reproducible profile of plasma lipidome alterations, not associated with symptom severity, medication, and demographic and environmental variables, and largely shared with BPD and MDD. This lipid alteration signature may represent a trait marker of severe psychiatric disorders, indicating its potential to be transformed into a clinically applicable testing procedure.

Stability over time of scores on psychiatric rating scales, questionnaires and cognitive tests in healthy controls

BACKGROUND

Case-only longitudinal studies are common in psychiatry. Further, it is assumed that psychiatric ratings and questionnaire results of healthy controls stay stable over foreseeable time ranges. For cognitive tests, improvements over time are expected, but data for more than two administrations are scarce.

AIMS

We comprehensively investigated the longitudinal course for trends over time in cognitive and symptom measurements for severe mental disorders. Assessments included the Trail Making Tests, verbal Digit Span tests, Global Assessment of Functioning, Inventory of Depressive Symptomatology, the Positive and Negative Syndrome Scale, and the Young Mania Rating Scale, among others.

METHOD

Using the data of control individuals (n = 326) from the PsyCourse study who had up to four assessments over 18 months, we modelled the course using linear mixed models or logistic regression. The slopes or odds ratios were estimated and adjusted for age and gender. We also assessed the robustness of these results using a longitudinal non-parametric test in a sensitivity analysis.

RESULTS

Small effects were detected for most cognitive tests, indicating a performance improvement over time (P < 0.05). However, for most of the symptom rating scales and questionnaires, no effects were detected, in line with our initial hypothesis.

CONCLUSIONS

The slightly but consistently improved performance in the cognitive tests speaks of a test-unspecific positive trend, while psychiatric ratings and questionnaire results remain stable over the observed period. These detectable improvements need to be considered when interpreting longitudinal courses. We therefore recommend recruiting control participants if cognitive tests are administered.

Genetic risk for psychiatric illness is associated with the number of hospitalizations of bipolar disorder patients

OBJECTIVES

Bipolar disorder (BD) has a highly heterogeneous clinical course that is characterized by relapses and increased health care utilization in a significant fraction of patients. A thorough understanding of factors influencing illness course is essential for predicting disorder severity and developing targeted therapies.

METHODS

We performed polygenic score analyses in four cohorts (N = 954) to test whether the genetic risk for BD, schizophrenia, or major depression is associated with a severe course of BD. We analyzed BD patients with a minimum illness duration of five years. The severity of the disease course was assessed by using the number of hospitalizations in a mental health facility and a composite measure of longitudinal illness severity (OPCRIT item 90).

RESULTS

Our analyses showed that higher polygenic scores for BD (β = 0.11, SE = 0.03, p = 1.17 × 10-3) and schizophrenia (β = 0.09, SE = 0.03, p = 4.24 × 10-3), but not for major depression, were associated with more hospitalizations. None of the investigated polygenic scores was associated with the composite measure of longitudinal illness severity (OPCRIT item 90).

LIMITATIONS

We could not account for non-genetic influences on disease course. Our clinical sample contained more severe cases.

CONCLUSIONS

This study demonstrates that the genetic risk burden for psychiatric illness is associated with increased health care utilization, a proxy for disease severity, in BD patients. The findings are in line with previous observations made for patients diagnosed with schizophrenia or major depression. Therefore, in the future psychiatric disorder polygenic scores might become helpful for stratifying patients with high risk of a chronic manifestation and predicting disease course.

Characterisation of age and polarity at onset in bipolar disorder

BACKGROUND

Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.

AIMS

To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.

METHOD

Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.

RESULTS

Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = -0.34 years, s.e. = 0.08), major depression (β = -0.34 years, s.e. = 0.08), schizophrenia (β = -0.39 years, s.e. = 0.08), and educational attainment (β = -0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.

CONCLUSIONS

AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.

Polygenic risk scores across the extended psychosis spectrum

As early detection of symptoms in the subclinical to clinical psychosis spectrum may improve health outcomes, knowing the probabilistic susceptibility of developing a disorder could guide mitigation measures and clinical intervention. In this context, polygenic risk scores (PRSs) quantifying the additive effects of multiple common genetic variants hold the potential to predict complex diseases and index severity gradients. PRSs for schizophrenia (SZ) and bipolar disorder (BD) were computed using Bayesian regression and continuous shrinkage priors based on the latest SZ and BD genome-wide association studies (Psychiatric Genomics Consortium, third release). Eight well-phenotyped groups (n = 1580; 56% males) were assessed: control (n = 305), lower (n = 117) and higher (n = 113) schizotypy (both groups of healthy individuals), at-risk for psychosis (n = 120), BD type-I (n = 359), BD type-II (n = 96), schizoaffective disorder (n = 86), and SZ groups (n = 384). PRS differences were investigated for binary traits and the quantitative Positive and Negative Syndrome Scale. Both BD-PRS and SZ-PRS significantly differentiated controls from at-risk and clinical groups (Nagelkerke's pseudo-R2: 1.3-7.7%), except for BD type-II for SZ-PRS. Out of 28 pairwise comparisons for SZ-PRS and BD-PRS, 9 and 12, respectively, reached the Bonferroni-corrected significance. BD-PRS differed between control and at-risk groups, but not between at-risk and BD type-I groups. There was no difference between controls and schizotypy. SZ-PRSs, but not BD-PRSs, were positively associated with transdiagnostic symptomology. Overall, PRSs support the continuum model across the psychosis spectrum at the genomic level with possible irregularities for schizotypy. The at-risk state demands heightened clinical attention and research addressing symptom course specifiers. Continued efforts are needed to refine the diagnostic and prognostic accuracy of PRSs in mental healthcare.

Interplay between the genetics of personality traits, severe psychiatric disorders and COVID-19 host genetics in the susceptibility to SARS-CoV-2 infection

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, with its impact on our way of life, is affecting our experiences and mental health. Notably, individuals with mental disorders have been reported to have a higher risk of contracting SARS-CoV-2. Personality traits could represent an important determinant of preventative health behaviour and, therefore, the risk of contracting the virus.

AIMS

We examined overlapping genetic underpinnings between major psychiatric disorders, personality traits and susceptibility to SARS-CoV-2 infection.

METHOD

Linkage disequilibrium score regression was used to explore the genetic correlations of coronavirus disease 2019 (COVID-19) susceptibility with psychiatric disorders and personality traits based on data from the largest available respective genome-wide association studies (GWAS). In two cohorts (the PsyCourse (n = 1346) and the HeiDE (n = 3266) study), polygenic risk scores were used to analyse if a genetic association between, psychiatric disorders, personality traits and COVID-19 susceptibility exists in individual-level data.

RESULTS

We observed no significant genetic correlations of COVID-19 susceptibility with psychiatric disorders. For personality traits, there was a significant genetic correlation for COVID-19 susceptibility with extraversion (P = 1.47 × 10^-5; genetic correlation 0.284). Yet, this was not reflected in individual-level data from the PsyCourse and HeiDE studies.

CONCLUSIONS

We identified no significant correlation between genetic risk factors for severe psychiatric disorders and genetic risk for COVID-19 susceptibility. Among the personality traits, extraversion showed evidence for a positive genetic association with COVID-19 susceptibility, in one but not in another setting. Overall, these findings highlight a complex contribution of genetic and non-genetic components in the interaction between COVID-19 susceptibility and personality traits or mental disorders.

Sexual dysfunction in patients with adult attention deficit hyperactivity disorder: A pilot study

Attention deficit hyperactivity disorder (ADHD) symptomatology, comorbid diseases, and pharmacological treatment with antidepressants can have a negative impact on sexual function, which in turn increases the likelihood of sexual dysfunction in people with ADHD. The objective of this pilot study was to differentiate and delineate possible sexual dysfunction in adults with ADHD. Adult ADHD patients (n = 32, cisgender / heterosexual) and healthy controls (n = 32, cisgender / heterosexual) filled out the DÄS-Zuf questionnaire with 59 items (Krieger, 2013). This questionnaire is divided into the scales “general contentment with life,” “anxiety/depression,” “sexual dysfunction” and “sexual satisfaction.” Patients with ADHD had significantly higher scores on single items measuring various aspects of sexual dysfunction as well as higher scores on the “anxiety/depression” scale and lower scores on the “general contentment with life” scale. Following repeated measures analyses of covariance in which the scale “anxiety/depression” was controlled as covariate, none of the previously differences for single items between ADHD patients and controls remained significant. ADHD patients with methylphenidate showed stronger physical sexual arousal compared to those without methylphenidate. The results of this pilot study suggest several explanations for sexual dysfunction among adults with ADHD and offer tentative routes for practical treatment approaches.

Medication Adherence in a Cross-Diagnostic Sample of Patients From the Affective-to-Psychotic Spectrum: Results From the PsyCourse Study

INTRODUCTION

According to the World Health Organization, medication adherence is defined as the extent to which a person's behavior corresponds with an agreed recommendation from a healthcare provider. Approximately 50% of patients do not take their medication as prescribed, and non-adherence can contribute to the progress of a disease. For patients suffering from mental diseases non-adherence plays an important role. Various factors have been proposed as contributing to non-adherence, however the literature remains heterogeneous dependent on the analyzed patient subgroups. This study comprehensively evaluates the association of sociodemographic, clinical, personality and quality of life related factors with medication adherence by analyzing data from the PsyCourse study. The PsyCourse study is a large and cross-diagnostic cohort of psychiatric patients from the affective-to-psychotic spectrum.

METHODS

The study sample comprised 1,062 patients from the PsyCourse study with various psychiatric diagnoses (mean [SD] age, 42.82 [12.98] years; 47.4% female). Data were analyzed to identify specific factors associated with medication adherence, and adherence was measured by a self-rating questionnaire. Odds ratios (OR) were estimated by a logistic regression for binary outcomes. Missing data were imputed using multiple imputation.

RESULTS

The following factors showed the strongest association with medication adherence: never having used illicit drugs (OR, 0.71), number of prescribed antipsychotics (OR, 1.40), the personality trait conscientiousness (OR, 1.26), and the environmental domain of quality of life (OR, 1.09).

CONCLUSION

In a large and cross-diagnostic sample, we could show that a higher level of conscientiousness, a higher number of antipsychotic medication, a better quality of life within the environmental domain, and the absence of substance abuse contribute to a better medication adherence independent of the underlying disorder.

An Investigation of Psychosis Subgroups With Prognostic Validation and Exploration of Genetic Underpinnings: The PsyCourse Study

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 (R2 = 0.41; 95% CI, 0.38-0.44), depression symptoms (R2 = 0.28; 95% CI, 0.25-0.32), global functioning (R2 = 0.16; 95% CI, 0.14-0.20), and quality of life (R2 = 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 η2 = 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.

The role of environmental stress and DNA methylation in the longitudinal course of bipolar disorder

BACKGROUND

Stressful life events influence the course of affective disorders, however, the mechanisms by which they bring about phenotypic change are not entirely known.

METHODS

We explored the role of DNA methylation in response to recent stressful life events in a cohort of bipolar patients from the longitudinal PsyCourse study (n = 96). Peripheral blood DNA methylomes were profiled at two time points for over 850,000 methylation sites. The association between impact ratings of stressful life events and DNA methylation was assessed, first by interrogating methylation sites in the vicinity of candidate genes previously implicated in the stress response and, second, by conducting an exploratory epigenome-wide association analysis. Third, the association between epigenetic aging and change in stress and symptom measures over time was investigated.

RESULTS

Investigation of methylation signatures over time revealed just over half of the CpG sites tested had an absolute difference in methylation of at least 1% over a 1-year period. Although not a single CpG site withstood correction for multiple testing, methylation at one site (cg15212455) was suggestively associated with stressful life events (p < 1.0 × 10^-5). Epigenetic aging over a 1-year period was not associated with changes in stress or symptom measures.

CONCLUSIONS

To the best of our knowledge, our study is the first to investigate epigenome-wide methylation across time in bipolar patients and in relation to recent, non-traumatic stressful life events. Limited and inconclusive evidence warrants future longitudinal investigations in larger samples of well-characterized bipolar patients to give a complete picture regarding the role of DNA methylation in the course of bipolar disorder.

The genetic relationship between educational attainment and cognitive performance in major psychiatric disorders

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.

The influence of religious activity and polygenic schizophrenia risk on religious delusions in schizophrenia

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.

[Analysis of the German state medical examination regarding psychiatrically relevant topics]

BACKGROUND

The second part of the state medical examination is an essential part of medical education in Germany. From 2006 until 2013, the second and third parts of the licensing examination were combined, thus earning this examination the reputation of being notoriously difficult to pass. The aim of this exploratory study was to examine psychiatric and psychotherapeutic questions in the written part of the second examination.

OBJECTIVES

This study analyzed the proportion of psychiatric and psychotherapeutic questions in the written part of the second leg of the German state medical examination. In a second step, a more detailed analysis aimed to identify more specific subject areas and to allocate diagnoses according to ICD-10, allowing a detailed overview of the presence of psychiatric topics.

MATERIAL AND METHODS

A total of 8 examinations from fall 2010 up to spring 2014 a were included in the analysis. Every examination comprised 320 questions, thus a total of 2560 questions were analyzed. All questions pertaining to psychiatric or psychotherapeutic topics were included. Questions were categorized according to a predefined set of subject areas and an ICD-10 diagnosis.

RESULTS

Out of the total of 2560 questions analyzed, 166 were categorized as being in psychiatry or psychotherapy, with each examination comprising an average of 20.75 (SD = 5.80) relevant questions. Most questions were allocated to the subject area of pharmacology (n = 53), followed by psychopathologic assessment (n = 27) and psychotherapy (n = 12). Sorted according to ICD-10 criteria, most questions could be assigned to the F3 category, the affective disorders group (21.9 %, n = 35).

CONCLUSION

In comparison to the actual strain placed on the healthcare system, the results indicate an underrepresentation of psychiatric disorders in the second part of the German state medical examination. The distribution of specific disorders mirrors the actual distribution at least in part; however, certain practically relevant disorders are severely underrepresented.

Computerised working-memory focused cognitive remediation therapy for psychosis--A preliminary study

BACKGROUND

Cognitive deficits are a core feature of schizophrenia and related psychotic disorders and are associated with decreased levels of functioning. Behavioural interventions have shown success in remediating these deficits; determining how best to maximise this benefit while minimising the cost is an important next step in optimising this intervention for clinical use.

AIMS

To examine the effects of a novel working-memory focused cognitive remediation (CR) training on cognitive difficulties based on internet delivery of training and weekly telephone support.

METHOD

Participants with a diagnosis of psychosis (n=56) underwent either 8 weeks of CR (approximately 20 h) or 8 weeks of treatment as usual (TAU). General cognitive ability, working memory and episodic memory were measured both pre and post intervention for all participants.

RESULTS

In addition to improvements on trained working memory tasks, CR training was associated with significant improvements in two tests of verbal episodic memory. No association between CR and changes in general cognitive ability was observed. Effect sizes for statistically significant changes in memory were comparable to those reported in the literature based primarily on 1:1 training.

CONCLUSIONS

The cognitive benefits observed in this non-randomised preliminary study indicate that internet-based working memory training can be an effective cognitive remediation therapy. The successes and challenges of an internet-based treatment are discussed.

Subtyping schizophrenia: A comparison of positive/negative and system-specific approaches

BACKGROUND

Schizophrenia is a heterogeneous disorder. Over the years, different approaches have been proposed to approach this heterogeneity by categorizing symptom patterns. The study aimed to compare positive/negative and system-specific approaches to subtyping.

METHODS

We used the Positive and Negative Syndrome Scale (PANSS) and Bern Psychopathology Scale (BPS), which consists of subscales for three domains (language, affect and motor behavior) that are hypothesized to be related to specific brain circuits, to assess cross-sectional psychopathological characteristics in a sample of 100 inpatients with schizophrenia spectrum disorders. We then categorized participants into positive/negative and system-specific subgroups to allow comparisons of the two approaches.

RESULTS

The analyses revealed correlations between the PANSS positive subscore and the BPS affective subscore (r=.446, p<.001) and between the PANSS negative subscore and the BPS motor behavior subscore (r=.227, p=.023). As regards the positive and negative subtype, more participants were classified as positive in the language-dominant subtype (30.3%) and affect-dominant subtype (30.3%), whereas more were classified as negative in the motor behavior-dominant subtype (44.4%). However, most patients met the criteria for the mixed subtype.

CONCLUSIONS

The results suggest that the positive/negative and system-specific approaches can be regarded as complementary. Future studies should examine both approaches in a longitudinal assessment of psychopathological symptoms and link them with qualitative-phenomenological approaches.

Functional outcome in major psychiatric disorders and associated clinical and psychosocial variables: A potential cross-diagnostic phenotype for further genetic investigations?

OBJECTIVES

Functional outcome has recently become of interest for cross-diagnostic subphenotype approaches in psychiatric genetics. Therefore, it is crucial to know about clinical, demographic and psychosocial variables that correlate with long-term functioning. Unfortunately, there is a lack of studies that directly compare the importance of correlates for functional outcome between different disorders.

METHODS

Applying regression models to samples of patients with schizophrenia (SZ, n = 238), bipolar disorder (BD, n = 533) and major depressive disorder (MDD, n = 398), we compared the magnitude of association of potential correlates with functional outcome, measured by the Global Assessment of Functioning (GAF) score.

RESULTS

Shared correlates for worse functional outcome were poor premorbid functioning, insidious illness onset and poor premorbid work or social adjustment in all three disorders, and negative symptomatology in SZ and BD. Disorder-specific correlates for SZ were longer duration of illness, lower functioning during episodes and being life-time single, for BD substance abuse and suicidality, and for MDD premorbid unemployment and having a premorbid personality disorder.

CONCLUSIONS

We found different patterns of correlates for long-term functioning in SZ, BD and MDD. Knowledge of these patterns may improve the quality of genetic investigations focussing on functional outcome.

Cortical thinning and caudate abnormalities in first episode psychosis and their association with clinical outcome

First episode psychosis (FEP) has been associated with structural brain changes, largely identified by volumetric analyses. Advances in neuroimaging processing have made it possible to measure geometric properties that may identify subtle structural changes not appreciated by a measure of volume alone. In this study we adopt complementary methods of assessing the structural integrity of grey matter in FEP patients and assess whether these relate to patient clinical and functional outcome at 3 year follow-up. 1.5 Tesla T1-weighted Magnetic Resonance (MR) images were acquired for 46 patients experiencing their first episode of psychosis and 46 healthy controls. Cerebral cortical thickness and local gyrification index (LGI) were investigated using FreeSurfer software. Volume and shape of the hippocampus, caudate and lateral ventricles were assessed using manual tracing and spherical harmonics applied for shape description. A cluster of cortical thinning was identified in FEP compared to controls; this was located in the right superior temporal gyrus, sulcus, extended into the middle temporal gyrus (lateral temporal cortex - LTC). Bilateral caudate volumes were significantly lower in FEP relative to controls and the right caudate also displayed regions of shape deflation in the FEP group. No significant structural abnormalities were identified in cortical LGI or hippocampal or lateral ventricle volume/shape. Neither LTC nor caudate abnormalities were related to change in symptom severity or global functioning 3 years later. LTC and caudate abnormalities are present at the first episode of psychosis but do not appear to directly affect clinical or functional outcome.

The phenotypic manifestations of rare CNVs in schizophrenia

There is compelling evidence for the role of copy number variants (CNVs) in schizophrenia susceptibility, and it has been estimated that up to 2-3% of schizophrenia cases may carry rare CNVs. Despite evidence that these events are associated with an increased risk across categorical neurodevelopmental disorders, there is limited understanding of the impact of CNVs on the core features of disorders like schizophrenia. Our objective was to evaluate associations between rare CNVs in differentially brain expressed (BE) genes and the core features and clinical correlates of schizophrenia. The sample included 386 cases of Irish ancestry with a diagnosis of schizophrenia, at least one rare CNV impacting any gene, and a core set of phenotypic measures. Statistically significant associations between deletions in differentially BE genes were found for family history of mental illness (decreased prevalence of all CNVs and deletions, unadjusted and adjusted) and for paternal age (increase in deletions only, unadjusted, among those with later ages at birth of patient). The strong effect of a lack of a family history on BE genes suggests that CNVs may comprise one pathway to schizophrenia, whereas a positive family history could index other genetic mechanisms that increase schizophrenia vulnerability. To our knowledge, this is the first investigation of the association between genome-wide CNVs and risk factors and sub-phenotypic features of schizophrenia beyond cognitive function.

Altered interhemispheric and temporal lobe white matter microstructural organization in severe chronic schizophrenia

Diffusion MRI investigations in schizophrenia provide evidence of abnormal white matter (WM) microstructural organization as indicated by reduced fractional anisotropy (FA) primarily in interhemispheric, left frontal and temporal WM. Using tract-based spatial statistics (TBSS), we examined diffusion parameters in a sample of patients with severe chronic schizophrenia. Diffusion MRI data were acquired on 19 patients with chronic severe schizophrenia and 19 age- and gender-matched healthy controls using a 64 gradient direction sequence, (b=1300 s/mm(2)) collected on a Siemens 1.5T MRI scanner. Diagnosis of schizophrenia was determined by Diagnostic and Statistical Manual for Mental Disorders 4th Edition (DSM-IV) Structured Clinical Interview for DSM disorder (SCID). Patients were treatment resistance, having failed to respond to at least two antipsychotic medications, and had prolonged periods of moderate to severe positive or negative symptoms. Analysis of diffusion parameters was carried out using TBSS. Individuals with chronic severe schizophrenia had significantly reduced FA with corresponding increased radial diffusivity in the genu, body, and splenium of the corpus callosum, the right posterior limb of the internal capsule, right external capsule, and the right temporal inferior longitudinal fasciculus. There were no voxels of significantly increased FA in patients compared with controls. A decrease in splenium FA was shown to be related to a longer illness duration. We detected widespread abnormal diffusivity properties in the callosal and temporal lobe WM regions in individuals with severe chronic schizophrenia who have not previously been exposed to clozapine. These deficits can be driven by a number of factors that are indistinguishable using in vivo diffusion-weighted imaging, but may be related to reduced axonal number or packing density, abnormal glial cell arrangement or function, and reduced myelin.

Uremic restless legs syndrome (RLS) and sleep quality in patients with end-stage renal disease on hemodialysis: potential role of homocysteine and parathyroid hormone

BACKGROUND

The aetiology of uremic restless legs syndrome (RLS) remains unclear. Our research investigated whether an elevated plasma concentration of the excitatory amino acid homocysteine might be associated with RLS occurrence in patients with chronic renal insufficiency on hemodialysis.

METHODS

Total plasma homocysteine as well as creatinine, urea, folate, parathyroid hormone, hemoglobin, iron, ferritin, phosphate, calcium, magnesium, and albumin levels were compared between 26 RLS-affected (RLSpos) and 26 non-affected (RLSneg) patients on chronic hemodialysis. We further compared subjective sleep quality between RLSpos and RLSneg patients using the Pittsburgh-Sleep-Quality-Index and investigated possible relationships between laboratory parameters and sleep quality.

RESULTS

Taking individual albumin concentrations into account, a significant positive correlation between total plasma homocysteine and RLS occurrence was observed (r= 0.246; p=0.045). Sleep quality was significantly more reduced in RLSpos compared to RLSneg patients and RLS severity correlated positively with impairment of sleep quality. Bad sleep quality in all patients was associated with higher concentrations of parathyroid hormone.

CONCLUSION

Our results suggest a possible aetiological role of homocysteine in uremic RLS. They confirm that uremic RLS is an important factor causing sleep impairment in patients on hemodialysis. Higher parathyroid hormone levels might also be associated with bad sleep quality in these patients.

Selected rapporteur summaries from the XX World Congress of Psychiatric Genetics, Hamburg, Germany, October 14-18, 2012

The XXth World Congress of Psychiatric Genetics (WCPG), sponsored by The International Society of Psychiatric Genetics (ISPG) took place in Hamburg, Germany on October 14-18, 2012. Approximately 600 participants gathered to discuss the latest findings in this rapidly advancing field. The following report was written by student travel awardees. Each was assigned sessions as rapporteurs. This manuscript represents topics covered in most, but not all, oral presentations during the conference, and some of the major notable new findings reported at this 2012 WCPG.