Sex difference in association of symptoms and white matter deficits in first-episode and drug-naive schizophrenia

Effects on Multimodal Connectivity Patterns in Female Schizophrenia During 8 Weeks of Antipsychotic Treatment

BACKGROUND AND HYPOTHESIS

Respective abnormal structural connectivity (SC) and functional connectivity (FC) have been reported in individuals with schizophrenia. However, transmodal associations between SC and FC following antipsychotic treatment, especially in female schizophrenia, remain unclear. We hypothesized that increased SC-FC coupling may be found in female schizophrenia, and could be normalized after antipsychotic treatment.

STUDY DESIGN

Sixty-four female drug-naïve patients with first-diagnosed schizophrenia treated with antipsychotic drugs for 8 weeks, and 55 female healthy controls (HCs) were enrolled. Magnetic resonance imaging (MRI) data were collected from HCs at baseline and from patients at baseline and after treatment. SC and FC were analyzed by network-based statistics, calculating nonzero SC-FC coupling of the whole brain and altered connectivity following treatment. Finally, an Elastic-net logistic regression analysis was employed to establish a predictive model for evaluating the clinical efficacy treatment.

STUDY RESULTS

At baseline, female schizophrenia patients exhibited abnormal SC in cortico-cortical, frontal-limbic, frontal-striatal, limbic-striatal, and limbic-cerebellar connectivity compared to HCs, while FC showed no abnormalities. Following treatment, cortico-cortical, frontal-limbic, frontal-striatal, limbic-striatal, temporal-cerebellar, and limbic-cerebellar connectivity were altered in both SC and FC. Additionally, SC-FC coupling of altered connectivity was higher in patients at baseline than in HC, trending toward normalization after treatment. Furthermore, identified FC or/and SC predicted changes in psychopathological symptoms and cognitive impairment among female schizophrenia following treatment.

CONCLUSIONS

SC-FC coupling may be a potential predictive biomarker of treatment response. Cortico-cortical, frontal-limbic, frontal-striatal, limbic-striatal, temporal-cerebellar, and limbic-cerebellar could represent major targets for antipsychotic drugs in female schizophrenia.

Genetic association between gene expression profiles in oligodendrocyte precursor cells and psychiatric disorders

Background

Although neuronal dysfunction has been the focus of many studies on psychiatric disorders, accumulating evidence suggests that white matter abnormalities and oligodendrocyte lineage cells, including oligodendrocyte precursor cells (OPCs), play an important role. Beyond their established contribution to myelination, synaptic genes in OPCs form connections to neurons and influence neuronal circuits and plasticity, thereby potentially contributing to psychiatric pathology.

Methods

We analyzed publicly available single-nucleus RNA sequencing (snRNA-seq) data from white matter cells of healthy donors with SCZ genome-wide association study (GWAS) summary statistics. We assessed cell-type-specific enrichment of SCZ-associated genetic variants and performed weighted gene co-expression network analysis (WGCNA) to identify disease-related gene modules in implicated cell types.

Results

OPCs exhibited significant enrichment of SCZ-associated genetic risk variants and showed pronounced specificity in gene expression patterns. Through WGCNA, we identified a distinct co-expression module in OPCs that was enriched for synaptic genes associated with SCZ.

Conclusion

The present results highlight the previously underappreciated role of OPCs in psychiatric disorders, suggesting that OPC-involved synaptic interactions may contribute to the pathophysiology of SCZ. This work underscores the importance of considering OPCs as active players in neural network dysfunction, with potential implications for future therapeutic strategies.

Characterizing multivariate regional hubs for schizophrenia classification, sex differences, and brain age estimation using explainable AI

Purpose

To investigate multivariate regional patterns for schizophrenia (SZ) classification, sex differences, and brain age by utilizing structural MRI, demographics, and explainable artificial intelligence (AI).

Methods

Various AI models were employed, and the outperforming model was identified for SZ classification, sex differences, and brain age predictions. For the SZ and sex classification tasks, support vector classifier (SVC), k-nearest neighbor (KNN), and deep learning neural network (DL) models were compared. In the case of regression-based brain age prediction, Lasso regression (LR), Ridge regression (RR), support vector regression (SVR), and DL models were compared. For each regression or classification task, the optimal model was further integrated with the Shapley additive explanations (SHAP) and the significant multivariate brain regional patterns were identified.

Results

Our results demonstrated that the DL model outperformed other models in SZ classification, sex differences, and brain age predictions. We then integrated outperforming DL model with SHAP, and this integrated DL-SHAP was used to identify the individualized multivariate regional patterns associated with each prediction. Using DL-SHAP approach, we found that individuals with SZ had anatomical changes particularly in left pallidum, left posterior insula, left hippocampus, and left putamen regions, and such changes associated with SZ were different between female and male patients. Finally, we further applied DL-SHAP method to brain age prediction and suggested important brain regions related to aging in health controls (HC) and SZ processes.

Conclusion

This study systematically utilized predictive modeling and novel explainable AI approaches and identified the complex multivariate brain regions involved with SZ classification, sex differences, and brain aging and built a deeper understanding of neurobiological mechanisms involved in the disease, offering new insights to future SZ diagnosis and treatments and laying the foundation of the development of precision medicine.

Sex differences in deep brain shape and asymmetry persist across schizophrenia and healthy individuals: A meta-analysis from the ENIGMA-Schizophrenia Working Group

Background

Schizophrenia (SCZ) is characterized by a disconnect from reality that manifests as various clinical and cognitive symptoms, and persistent neurobiological abnormalities. Sex-related differences in clinical presentation imply separate brain substrates. The present study characterized deep brain morphology using shape features to understand the independent effects of diagnosis and sex on the brain, and to determine whether the neurobiology of schizophrenia varies as a function of sex.

Methods

This study analyzed multi-site archival data from 1,871 male (M) and 955 female (F) participants with SCZ, and 2,158 male and 1,877 female healthy controls (CON) from twenty-three cross-sectional samples from the ENIGMA Schizophrenia Workgroup. Harmonized shape analysis protocols were applied to each site's data for seven deep brain regions obtained from T1-weighted structural MRI scans. Effect sizes were calculated for the following main contrasts: 1) Sex effects;2) Diagnosis-by-Sex interaction; 3) within sex tests of diagnosis; 4) within diagnosis tests of sex differences. Meta-regression models between brain structure and clinical variables were also computed separately in men and women with schizophrenia.

Results

Mass univariate meta-analyses revealed more concave-than-convex shape differences in all regions for women relative to men, across diagnostic groups ( d = -0.35 to 0.20, SE = 0.02 to 0.07); there were no significant diagnosis-by-sex interaction effects. Within men and women separately, we identified more-concave-than-convex shape differences for the hippocampus, amygdala, accumbens, and thalamus, with more-convex-than-concave differences in the putamen and pallidum in SCZ ( d = -0.30 to 0.30, SE = 0.03 to 0.10). Within CON and SZ separately, we found more-concave-than-convex shape differences in the thalamus, pallidum, putamen, and amygdala among females compared to males, with mixed findings in the hippocampus and caudate ( d = -0.30 to 0.20, SE = 0.03 to 0.09). Meta-regression models revealed similarly small, but significant relationships, with medication and positive symptoms in both SCZ-M and SCZ-F.

Conclusions

Sex-specific variation is an overriding feature of deep brain shape regardless of disease status, underscoring persistent patterns of sex differences observed both within and across diagnostic categories, and highlighting the importance of including it as a critical variable in studies of neurobiology. Future work should continue to explore these dimensions independently to determine whether these patterns of brain morphology extend to other aspects of neurobiology in schizophrenia, potentially uncovering broader implications for diagnosis and treatment.

Key Points

Statistical analyses revealed significant main effects for diagnosis and sex in deep brain shape morphology. Among patients with schizophrenia, there was a pattern of thinning and surface contraction in the bilateral hippocampus, amygdala, accumbens, and thalamus, and a pattern of significant thickening and surface expansion in the bilateral putamen and pallidum compared to healthy control participants. Between males and females, there was a pattern of significant thinning and surface contraction in the bilateral thalamus, pallidum, putamen, and amygdala in females compared to males.There was no significant interaction between diagnosis and biological sex, suggesting that sex differences in deep brain shape and asymmetry among patients with schizophrenia reflect those observed in healthy individuals.Small but statistically significant relationships exist between brain structure and clinical correlates of schizophrenia were similar for both men and women with the disease, such that higher CPZ was associated with shape-derived thinning and surface contraction in the caudate, accumbens, hippocampus, amygdala, and thalamus, and elevated positive symptoms were associated with shape-derived thinning and surface contraction in the bilateral caudate, right hippocampus, and right amygdala.

Association of P50 with social function, but not with cognition in patients with first-episode schizophrenia

Functional deficits including cognitive impairment and social dysfunction are the core symptoms of schizophrenia (SCZ), and sensory gating (SG) deficits may be involved in the pathological mechanism of functional deficits in SCZ. This study was to investigate the relationship between defective P50 inhibition and functional deficits in first-episode drug naïve (FEDN) SCZ patients. A total of 95 FEDN SCZ patients and 53 healthy controls (HC) were recruited. The Chinese version of UCSD Performance-Based Skills (UPSA), MATRICS Consensus Cognitive Battery (MCCB), and EEG system were used to assess the social function, cognitive performance, and P50 inhibition, respectively. The MCCB total score and eight domain scores were significantly lower in patients with FEDN SCZ than those in HC (all p < 0.05). The UPSA total score and financial skills scores were also significantly lower in SCZ patients than that in the HC (all p < 0.05). Compared with HC, patients with FEDF SCZ had a higher P50 ratio (all p < 0.05). There was no correlation between P50 components and MCCB scores in patients with FEDF SCZ. However, there was only a correlation between the P50 ratio and UPSA financial skills, communication skills, or total score in patients (all p < 0.05). Defective P50 inhibition in FEDN SCZ patients may be associated with social dysfunction but not cognitive impairment, suggesting that the social dysfunction and cognitive impairment of patients with FEDN SCZ may have different pathogenic mechanisms.

Erythrocyte membrane fatty acid concentrations and myelin integrity in young people at ultra-high risk of psychosis

Decreased white matter (WM) integrity and disturbance in fatty acid composition have been reported in individuals at ultra-high risk of psychosis (UHR). The current study is the first to investigate both WM integrity and erythrocyte membrane polyunsaturated fatty acid (PUFA) levels as potential risk biomarkers for persistent UHR status, and global functioning in UHR individuals. Forty UHR individuals were analysed at baseline for erythrocyte membrane PUFA concentrates. Tract-based spatial statistics (TBSS) was used to analyse fractional anisotropy (FA) and diffusivity measures. Measures of global functioning and psychiatric symptoms were evaluated at baseline and at 12-months. Fatty acids and WM indices did not predict functional outcomes at baseline or 12-months. Significant differences were found in FA between UHR remitters and non-remitters (individuals who no longer met UHR criteria versus those who continued to meet criteria at 12-months). Docosahexaenoic acid (DHA) was found to be a significant predictor of UHR status at 12-months, as was the interaction between the sum of ώ-3 and whole brain FA, and the interaction between the right anterior limb of the internal capsule and the sum of ώ-3. The results confirm that certain fatty acids have a unique relationship with WM integrity in UHR individuals.

Gender differences in cognitive improvements after two months of atypical antipsychotic treatment in first episode schizophrenia

Aims

This study aims to explore the gender differences in cognitive improvements after two months of atypical antipsychotic treatment in first episode schizophrenia (FES).

Methods

82 patients with FES, including 50 male patients and 32 female patients, were enrolled in the present study. Positive and Negative Syndrome Scale (PANSS) and MATRICS Consensus Cognitive Battery (MCCB) were respectively conducted to evaluate the clinical symptoms and cognitive function of patients with FES at baseline and after treatment. Repeated measure ANOVA was performed to compare gender differences in cognitive domains scores between baseline and 2-month follow-up. Stepwise liner regression model was performed to explore the effect factors of cognitive improvements in patients.

Results

There was no significant difference in age of onset, education years, PANSS scores, duration of untreated psychosis and Olanzapine equivalent doses between male and female patients (all p > 0.05). In the comparisons of cognition function, male patients exhibited better performance in social cognition compared with female patients at baseline (t = 3.20, p < 0.05). After treatment, improvements of attention/vigilance and working memory were both found in male patients and female patients (attention/vigilance, F = 11.867, p < 0.05; working memory, F = 18.265, p < 0.05). In addition, improvement of speed of information processing was only found in female patients (F = 11.65, p < 0.01). Significant interaction between time and gender was found in speed information of processing (F = 4.140, p = 0.045). Stepwise liner regression model revealed that improvements of negative symptoms promote improvements of cognitive function in female patients (all p < 0.05).

Conclusions

Our findings revealed gender differences of cognitive improvements in patients with FES after 2-month treatment. It provides new evidence for gender differences in cognitive symptoms of schizophrenia, and also provides preliminary clues for further individualized cognitive intervention strategies.

A comprehensive update on genetic inheritance, epigenetic factors, associated pathology, and recent therapeutic intervention by gene therapy in schizophrenia

Schizophrenia is a severe psychological disorder in which reality is interpreted abnormally by the patient. The symptoms of the disease include delusions and hallucinations, associated with extremely disordered behavior and thinking, which may affect the daily lives of the patients. Advancements in technology have led to understanding the dynamics of the disease and the identification of the underlying causes. Multiple investigations prove that it is regulated genetically, and epigenetically, and is affected by environmental factors. The molecular and neural pathways linked to the regulation of schizophrenia have been extensively studied. Over 180 Schizophrenic risk loci have now been recognized due to several genome-wide association studies (GWAS). It has been observed that multiple transcription factors (TF) binding-disrupting single nucleotide polymorphisms (SNPs) have been related to gene expression responsible for the disease in cerebral complexes. Copy number variation, SNP defects, and epigenetic changes in chromosomes may cause overexpression or underexpression of certain genes responsible for the disease. Nowadays, gene therapy is being implemented for its treatment as several of these genetic defects have been identified. Scientists are trying to use viral vectors, miRNA, siRNA, and CRISPR technology. In addition, nanotechnology is also being applied to target such genes. The primary aim of such targeting was to either delete or silence such hyperactive genes or induce certain genes that inhibit the expression of these genes. There are challenges in delivering the gene/DNA to the site of action in the brain, and scientists are working to resolve the same. The present article describes the basics regarding the disease, its causes and factors responsible, and the gene therapy solutions available to treat this disease.

Traveling Subject-Informed Harmonization Increases Reliability of Brain Diffusion Tensor and Neurite Mapping

Diffusion-weighted magnetic resonance imaging (dMRI) of brain has helped elucidate the microstructural changes of psychiatric and neurodegenerative disorders. Inconsistency between MRI models has hampered clinical application of dMRI-based metrics. Using harmonized dMRI data of 300 scans from 69 traveling subjects (TS) scanning the same individuals at multiple conditions with 13 MRI models and 2 protocols, the widely-used metrics such as diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) were evaluated before and after harmonization with a combined association test (ComBat) or TS-based general linear model (TS-GLM). Results showed that both ComBat and TS-GLM significantly reduced the effects of the MRI site, model, and protocol for diffusion metrics while maintaining the intersubject biological effects. The harmonization power of TS-GLM based on TS data model is more powerful than that of ComBat. In conclusion, our research demonstrated that although ComBat and TS-GLM harmonization approaches were effective at reducing the scanner effects of the site, model, and protocol for DTI and NODDI metrics in WM, they exhibited high retainability of biological effects. Therefore, we suggest that, after harmonizing DTI and NODDI metrics, a multisite study with large cohorts can accurately detect small pathological changes by retaining pathological effects.

Structural impairment in superficial and deep white matter in schizophrenia

OBJECTIVE

Although disconnectivity among brain regions has been one of the main hypotheses for schizophrenia, the superficial white matter (SWM) has received less attention in schizophrenia research than the deep white matter (DWM) owing to the challenge of consistent reconstruction across subjects.

METHODS

We obtained the diffusion magnetic resonance imaging (dMRI) data of 223 healthy controls and 143 patients with schizophrenia. After harmonising the raw dMRIs from three different studies, we performed whole-brain two-tensor tractography and fibre clustering on the tractography data. We compared the fractional anisotropy (FA) of white matter tracts between healthy controls and patients with schizophrenia. Spearman's rho was adopted for the associations with clinical symptoms measured by the Positive and Negative Syndrome Scale (PANSS). The Bonferroni correction was used to adjust multiple testing.

RESULTS

Among the 33 DWM and 8 SWM tracts, patients with schizophrenia had a lower FA in 14 DWM and 4 SWM tracts than healthy controls, with small effect sizes. In the patient group, the FA deviations of the corticospinal and superficial-occipital tracts were negatively correlated with the PANSS negative score; however, this correlation was not evident after adjusting for multiple testing.

CONCLUSION

We observed the structural impairments of both the DWM and SWM tracts in patients with schizophrenia. The SWM could be a potential target of interest in future research on neural biomarkers for schizophrenia.

Sex differences in the clinical presentation of early psychosis in a primary care setting

Primary care is an important part of the help-seeking pathway for young people experiencing early psychosis, but sex differences in clinical presentation in these settings are unexplored. We aimed to identify sex differences in clinical presentation to primary care services in the 1-year period prior to a first diagnosis of psychotic disorder. We identified first-onset cases of non-affective psychotic disorder over a 10-year period (2005-2015) using health administrative data linked with electronic medical records (EMRs) from primary care (n = 465). Detailed information on encounters in the year prior to first diagnosis was abstracted, including psychiatric symptoms, other relevant behaviours, and diagnoses recorded by the family physician (FP). We used modified Poisson regression models to examine sex differences in the signs, symptoms, and diagnoses recorded by the FP, adjusting for various clinical and sociodemographic factors. Positive symptoms (PR = 0.76, 95%CI: 0.58, 0.98) and substance use (PR = 0.54, 95%CI: 0.40, 0.72) were less prevalent in the medical records of women. Visits by women were more likely to be assigned a diagnosis of depression or anxiety (PR = 1.18, 95%CI: 1.00, 1.38), personality disorder (PR = 5.49, 95%CI: 1.22, 24.62), psychological distress (PR = 11.29, 95%CI: 1.23, 103.91), and other mental or behavioral disorders (PR = 3.49, 95%CI: 1.14, 10.66) and less likely to be assigned a diagnosis of addiction (PR = 0.33, 95%CI: 0.13, 0.87). We identified evidence of sex differences in the clinical presentation of early psychosis and recorded diagnoses in the primary care EMR. Further research is needed to better understand sex differences in clinical presentation in the primary care context, which can facilitate better understanding, detection, and intervention for first-episode psychotic disorders.

Sex and gender differences in symptoms of early psychosis: a systematic review and meta-analysis

First-episode psychosis (FEP) can be quite variable in clinical presentation, and both sex and gender may account for some of this variability. Prior literature on sex or gender differences in symptoms of psychosis have been inconclusive, and a comprehensive summary of evidence on the early course of illness is lacking. The objective of this study was to conduct a systematic review and meta-analysis of the literature to summarize prior evidence on the sex and gender differences in the symptoms of early psychosis. We conducted an electronic database search (MEDLINE, Scopus, PsycINFO, and CINAHL) from 1990 to present to identify quantitative studies focused on sex or gender differences in the symptoms of early psychosis. We used random effects models to compute pooled standardized mean differences (SMD) and risk ratios (RR), with 95% confidence intervals (CI), for a range of symptoms. Thirty-five studies met the inclusion criteria for the systematic review, and 30 studies were included in the meta-analysis. All studies examined sex differences. Men experienced more severe negative symptoms (SMD =  - 0.15, 95%CI =  - 0.21, - 0.09), whereas women experienced more severe depressive symptoms (SMD = 0.21, 95%CI = 0.14, 0.27) and had higher functioning (SMD = 0.16, 95%CI = 0.10, 0.23). Women also had a lower prevalence of substance use issues (RR = 0.65, 95%CI = 0.61, 0.69). Symptoms of early psychosis varied between men and women; however, we were limited in our ability to differentiate between biological sex and gender factors. These findings may help to inform early detection and intervention efforts to better account for sex and gender differences in early psychosis presentation.

SFARI genes and where to find them; modelling Autism Spectrum Disorder specific gene expression dysregulation with RNA-seq data

Autism Spectrum Disorders (ASD) have a strong, yet heterogeneous, genetic component. Among the various methods that are being developed to help reveal the underlying molecular aetiology of the disease one approach that is gaining popularity is the combination of gene expression and clinical genetic data, often using the SFARI-gene database, which comprises lists of curated genes considered to have causative roles in ASD when mutated in patients. We build a gene co-expression network to study the relationship between ASD-specific transcriptomic data and SFARI genes and then analyse it at different levels of granularity. No significant evidence is found of association between SFARI genes and differential gene expression patterns when comparing ASD samples to a control group, nor statistical enrichment of SFARI genes in gene co-expression network modules that have a strong correlation with ASD diagnosis. However, classification models that incorporate topological information from the whole ASD-specific gene co-expression network can predict novel SFARI candidate genes that share features of existing SFARI genes and have support for roles in ASD in the literature. A statistically significant association is also found between the absolute level of gene expression and SFARI's genes and Scores, which can confound the analysis if uncorrected. We propose a novel approach to correct for this that is general enough to be applied to other problems affected by continuous sources of bias. It was found that only co-expression network analyses that integrate information from the whole network are able to reveal signatures linked to ASD diagnosis and novel candidate genes for the study of ASD, which individual gene or module analyses fail to do. It was also found that the influence of SFARI genes permeates not only other ASD scoring systems, but also lists of genes believed to be involved in other neurodevelopmental disorders.

NKCC1 to KCC2 mRNA Ratio in Schizophrenia and Its Psychopathology: a Case-Control Study

Schizophrenia (SCZ) is a debilitating, destructive, and chronic mental disorder and affects approximately one percent of the human population. Diagnosis in psychiatry is based on the patient's descriptions of his/her symptoms, interviewer's observations, history of disorder over time, and response to treatment. All of these data measure phenotype-based functions. But it appears that accurate diagnosis of such a complex disorder must be based on valid and reliable factors. In the present study, gene selection was based on the possible role of γ-aminobutyric acid (GABA) in psychopathology of SCZ and expression in blood. We evaluated the association of Na⁺-K⁺-Cl^- co-transporter 1 (NKCC1) and K⁺-Cl^- co-transporter 2 (KCC2) genes' messenger ribonucleic acid (mRNA) levels, and also the NKCC1/KCC2 ratio with positive and negative syndrome scale (PANSS) and brief psychiatric rating scale (BPRS) scores in an SCZ group. By using real-time PCR (RT-PCR), the present study is the first attempt to explore levels of NKCC1 and KCC2 expression at mRNA level and their relative expression in human peripheral blood of patients with SCZ. Our results showed that the NKCC1 to KCC2 mRNA ratio is significantly increased (but based on the delta cycle of threshold [∆Ct] is significantly lower) in the total sample of cases rather than controls (p = 0.045) and also higher in male sample cases rather than male controls (p = 0.016). In female samples, we found a trend toward a significant effect between the case and control participants (p = 0.075). We also found statistically significant association between mRNA of NKCC1 and KCC2 genes and NKCC1/KCC2 mRNA ratio with the positive and negative syndrome scale (PANSS) and brief psychiatric rating scale (BPRS) scores.

Males and females with first episode psychosis present distinct profiles of social cognition and metacognition

Deficits in social cognition and metacognition impact the course of psychosis. Sex differences in social cognition and metacognition could explain heterogeneity in psychosis. 174 (58 females) patients with first-episode psychosis completed a clinical, neuropsychological, social cognitive, and metacognitive assessment. Subsequent latent profile analysis split by sex yielded two clusters common to both sexes (a Homogeneous group, 53% and 79.3%, and an Indecisive group, 18.3% and 8.6% of males and females, respectively), a specific male profile characterized by presenting jumping to conclusions (28.7%) and a specific female profile characterized by cognitive biases (12.1%). Males and females in the homogeneous profile seem to have a more benign course of illness. Males with jumping to conclusions had more clinical symptoms and more neuropsychological deficits. Females with cognitive biases were younger and had lower self-esteem. These results suggest that males and females may benefit from specific targeted treatment and highlights the need to consider sex when planning interventions.

Bridging structural MRI with cognitive function for individual level classification of early psychosis via deep learning

INTRODUCTION

Recent efforts have been made to apply machine learning and deep learning approaches to the automated classification of schizophrenia using structural magnetic resonance imaging (sMRI) at the individual level. However, these approaches are less accurate on early psychosis (EP) since there are mild structural brain changes at early stage. As cognitive impairments is one main feature in psychosis, in this study we apply a multi-task deep learning framework using sMRI with inclusion of cognitive assessment to facilitate the classification of patients with EP from healthy individuals.

METHOD

Unlike previous studies, we used sMRI as the direct input to perform EP classifications and cognitive estimations. The proposed deep learning model does not require time-consuming volumetric or surface based analysis and can provide additionally cognition predictions. Experiments were conducted on an in-house data set with 77 subjects and a public ABCD HCP-EP data set with 164 subjects.

RESULTS

We achieved 74.9 ± 4.3% five-fold cross-validated accuracy and an area under the curve of 71.1 ± 4.1% on EP classification with the inclusion of cognitive estimations.

DISCUSSION

We reveal the feasibility of automated cognitive estimation using sMRI by deep learning models, and also demonstrate the implicit adoption of cognitive measures as additional information to facilitate EP classifications from healthy controls.

Sex Differences in Obesity and Cognitive Function in Chinese Elderly Patients With Chronic Schizophrenia

BACKGROUND

It is well known that schizophrenia is associated with sex differences. However, no study has explored the sex differences in obesity and cognitive function in elderly Chinese patients with schizophrenia.

OBJECTIVE

This study aimed to compare sex differences in obesity and cognitive function in elderly Chinese individuals with schizophrenia.

METHODS

A total of 304 elderly patients with schizophrenia and 130 sex- and age-matched healthy controls from the community were recruited. Demographic, clinical, and lipid parameters were collected for all subjects. The Montreal Cognitive Assessment (MoCA) was used to assess the global cognitive functions of the participants, while the Positive and Negative Syndrome Scale (PANSS) was used to assess psychopathological symptoms in patients with schizophrenia.

RESULTS

Of the patients with schizophrenia, the prevalence of obesity in men and women was 11.7% (19/163) and 21.3% (30/141), respectively. The score (14.51 ± 6.504) of MOCA in elderly male patients with schizophrenia was significantly higher than that (11.40 ± 6.822) in female patients. There was a positive correlation between the MOCA scores and body mass index (BMI) (r=0.206, p=0.018) in male elderly patients with schizophrenia. Conversely, the MOCA scores of female elderly patients with schizophrenia did not correlate with BMI (p>0.05). However, we found no sex differences in obesity and cognition among control older adults.

CONCLUSIONS

Our findings suggest that there are significant sex differences in obesity and cognitive function in elderly Chinese patients with schizophrenia.

White matter impairments in patients with schizophrenia: A multisite diffusion MRI study

There is a lack of convincing and replicative findings regarding white matter abnormalities in schizophrenia. Several multisite diffusion magnetic resonance imaging (dMRI) studies have been conducted to increase statistical power and reveal subtle white matter changes. Data pooling methods are crucial in joint analysis to compensate for the use of different scanners and image acquisition parameters. A harmonization method using raw dMRI data was developed to overcome the limited generalizability of previous data pooling methods. We obtained dMRI data of 242 healthy controls and 190 patients with schizophrenia from four different study sites. After applying the harmonization method to the raw dMRI data, a two-tensor whole-brain tractography was performed, and diffusion measures were compared between the two groups. The correlation of fractional anisotropy (FA) with the positive and negative symptoms was evaluated, and the interaction effect of diagnosis-by-age, age-squared, and sex was examined. The following white matter tracts showed significant group differences in the FA: the right superior longitudinal fascicle (SLF), the left-to-right lateral orbitofrontal commissural tract, pars orbitalis (pOr-pOr) commissural tract, and pars triangularis (pTr-pTr) commissural tract. The FA of the right SLF and pTr-pTr commissural tract were significantly associated with the Positive and Negative Syndrome Scale (PANSS) positive and negative scores. No significant interaction effect was observed. These findings add to the evidence on structural brain abnormalities in schizophrenia and can aid in obtaining a better understanding of the biological foundations of schizophrenia.

Sex differences in P50 inhibition defects with psychopathology and cognition in patients with first-episode schizophrenia

BACKGROUND

A large number of studies have shown that the pathophysiology of schizophrenia may be involved in sensory gating that appears to be P50 inhibition. However, few studies have investigated the relationship between clinical symptoms, cognitive impairment and sensory gating disorders in patients with first-episode schizophrenia. The purpose of this study was to explore the sex differences in the relationship between clinical symptoms, cognitive impairment and P50 inhibition defects in patients with first-episode schizophrenia, which has not been reported.

METHODS

130 patients with first-episode schizophrenia (53 males and 77 females) and 189 healthy controls (87 males and 102 females) participated in the study. Positive and Negative Syndrome Scale (PANSS) was used to evaluate the patients' psychopathological symptoms, and the 64-channel electroencephalogram (EEG) system was used to record the P50 inhibition.

RESULTS

Male patients had higher PANSS negative symptom, general psychopathology, cognitive factor and total scores than female patients (all p < 0.01). The S1 amplitude was smaller in male than female patients (all p < 0.05). Multiple regression analysis showed that in male patients, S1 latency was contributor to negative symptoms, while S1 latency, S2 latency, age, and smoking status were contributors to cognitive factor (all p < 0.05). In female patients, no P50 component was found to be an independent contributor to PANSS scores (all p > 0.05).

CONCLUSIONS

Our results indicate that there is a sex difference in the relationship between clinical symptoms, cognitive impairment and P50 inhibition defects in Chinese Han patients with first-episode schizophrenia.

Sex Difference in Comorbid Depression in First-Episode and Drug-Naive Patients With Schizophrenia: Baseline Results From the Depression in Schizophrenia in China Study

OBJECTIVE

Comorbid depression is common in schizophrenia, and sex differences are prominent in many aspects of schizophrenia. However, few studies have investigated sex difference in comorbid depression in schizophrenia. This large sample study aimed to investigate sex differences in first-episode drug-naive (FEDN) patients with schizophrenia comorbid major depressive episode (SZ-MDE).

METHODS

A total of 996 FEDN patients with schizophrenia (472 males/524 females) were recruited. The 17-item Hamilton Depression Rating Scale and Positive and Negative Syndrome Scale (PANSS) were applied.

RESULTS

There was no difference in the prevalence of comorbid MDE between male and female patients with schizophrenia. Among SZ-MDE patients, men had more severe psychotic symptoms (scores of PANSS total scale, negative scale, and general psychopathology scale), more severe depressive symptoms, and higher proportion of severe depression than women (all p < .001). The early onset age of schizophrenia, smoking, and PANSS positive score were the risk factors for comorbid MDE only in female patients with schizophrenia (all p < .05). Furthermore, in female patients with SZ-MDE, smoking was associated with the severity category of depression (p = .001, odds ratio = 2.70). Multiple variable regression demonstrated that the Hamilton Depression Rating Scale score correlated with PANSS general psychopathology (p = .01) and total scores (p = .04) in female SZ-MDE.

CONCLUSIONS

Our results indicate sex differences in proportion of severe depression, clinical symptoms, and factors of comorbid MDE in FEDN patients with schizophrenia. These sex differences have clinical implications for the treatment of depression as related to the nature and severity of psychopathological symptoms in patients with schizophrenia.

Global fractional anisotropy predicts transition to psychosis after 12 months in individuals at ultra-high risk for psychosis

OBJECTIVE

Psychosis spectrum disorders are associated with cerebral changes, but the prognostic value and clinical utility of these findings are unclear. Here, we applied a multivariate statistical model to examine the predictive accuracy of global white matter fractional anisotropy (FA) for transition to psychosis in individuals at ultra-high risk for psychosis (UHR).

METHODS

110 UHR individuals underwent 3 Tesla diffusion-weighted imaging and clinical assessments at baseline, and after 6 and 12 months. Using logistic regression, we examined the reliability of global FA at baseline as a predictor for psychosis transition after 12 months. We tested the predictive accuracy, sensitivity and specificity of global FA in a multivariate prediction model accounting for potential confounders to FA (head motion in scanner, age, gender, antipsychotic medication, parental socioeconomic status and activity level). In secondary analyses, we tested FA as a predictor of clinical symptoms and functional level using multivariate linear regression.

RESULTS

Ten UHR individuals had transitioned to psychosis after 12 months (9%). The model reliably predicted transition at 12 months (χ²  = 17.595, p = 0.040), accounted for 15-33% of the variance in transition outcome with a sensitivity of 0.70, a specificity of 0.88 and AUC of 0.87. Global FA predicted level of UHR symptoms (R²  = 0.055, F = 6.084, p = 0.016) and functional level (R²  = 0.040, F = 4.57, p = 0.036) at 6 months, but not at 12 months.

CONCLUSION

Global FA provided prognostic information on clinical outcome and symptom course of UHR individuals. Our findings suggest that the application of prediction models including neuroimaging data can inform clinical management on risk for psychosis transition.

Sex-differential associations between cognitive impairments and white matter abnormalities in first episode and drug-naïve schizophrenia

AIM

Previous evidence has suggested that schizophrenia patients may display sex differences in cognitive impairments and cognitive impairments are related to disrupted white matter (WM) microstructure. The current research aims to address the intriguing possibility for the sex-specific association between cognitive deficits and WM abnormalities in first-episode and drug-naïve schizophrenia.

METHODS

Cognitive performance on the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) was measured in 39 FEND patients (females:males = 23:16) and 30 healthy controls (females:males = 17:13), together with whole-brain WM fractional anisotropy (FA) values determined using voxel-based diffusion tensor imaging. Correlations between cognitive performance and FA values were assessed.

RESULTS

Patients performed significantly worse than healthy controls in the total score and most of the subscores of MCCB. Female patients displayed better cognitive performance than male patients on the Trail Making A Test, the Hopkins Verbal Learning Test and the Spatial Span Test in the Wechsler Memory Scale. More importantly, sex-differential association between cognitive performance and FA values was found in patients, but not in healthy controls. In particular, FA values in the cerebellum were negatively correlated with the continuous performance and digital sequence scores in male patients but positively correlated with the performance on the Spatial Span Test in the Wechsler Memory Scale in female patients.

CONCLUSIONS

These findings suggest sex-specific neurobiological substrates involved in cognitive deficits in early-onset schizophrenia and have important implications for differentially targeted interventions between males and females.

Genetic Modulators of Traumatic Brain Injury in Animal Models and the Impact of Sex-Dependent Effects

Traumatic brain injury (TBI) is a major health problem causing disability and death worldwide. There is no effective treatment, due in part to the complexity of the injury pathology and factors affecting its outcome. The extent of brain injury depends on the type of insult, age, sex, lifestyle, genetic risk factors, socioeconomic status, other co-injuries, and underlying health problems. This review discusses the genes that have been directly tested in TBI models, and whether their effects are known to be sex-dependent. Sex differences can affect the incidence, symptom onset, pathology, and clinical outcomes following injury. Adult males are more susceptible at the acute phase and females show greater injury in the chronic phase. TBI is not restricted to a single sex; despite variations in the degree of symptom onset and severity, it is important to consider both female and male animals in TBI pre-clinical research studies.

White Matter Integrity of the Corpus Callosum and Psychopathological Dimensions in Deficit and Non-Deficit Schizophrenia Patients

Deficit syndrome (DS) is a subtype of schizophrenia characterized by primary persistent negative symptoms. The corpus callosum (CC) appears to be related to psychopathology in schizophrenia. This study assessed white matter integrity in the CC using diffusion tensor imaging (DTI) in deficit and non-deficit schizophrenia (NDS) patients. We also investigated the psychopathological dimensions of schizophrenia and their relationship to CC integrity. Fifteen DS patients, 40 NDS patients, and 30 healthy controls (HC) underwent psychiatric evaluation and neuroimaging. We divided the CC into five regions and assessed their fractional anisotropy (FA) and mean diffusivity (MD). Psychopathology was assessed with the Positive and Negative Syndrome Scale. DS patients had lower FA than NDS patients and HC, and higher MD in Region 5 of the CC than did HC. NDS patients had higher MD in Region 4 of the CC. The patient groups differed in terms of negative symptoms. After differentiating clinical groups and HC, no significant correlations were observed between DTI measures and psychopathological symptoms. Our results suggest that DS and NDS are characterized by minor impairments of the posterior CC. We confirmed that DS patients have greater negative psychopathology than NDS patients. Our results are preliminary, and further studies are needed.

Sex differences in schizophrenia relevant to clinical care

Introduction: Most medical diagnoses present somewhat differently in men and women, more so at specific periods of life. Treatment effects may also differ. This is true for schizophrenia, where premorbid effects are experienced earlier in life in boys than in girls, and where symptoms and outcomes differ.Areas covered: This review does not cover all the differences that have been reported between men and women but, instead, focuses on the ones that carry important implications for clinical care: effective antipsychotic doses, medication side effects, symptom fluctuation due to hormonal levels, comorbidities, and women's requirements for prenatal, obstetric, postpartum, and parenting support.Expert opinion: Of consequence to schizophrenia, sex-biased genes, epigenetic modifications, and sex steroids all impact the structure and function of the brain. Furthermore, life experiences and social roles exert major sex-specific influences. The co-morbidities that accompany schizophrenia also affect men and women to different degrees. This review offers several examples of sex-specific intervention and concludes that gold standard treatment must look beyond symptoms and address all the physiologic, psychologic, and social role needs of men and women suffering from this psychiatric disorder.

Sex-specific Association of Antipsychotic-induced Weight Gain and Treatment Response for Antipsychotic-Naive First Episode Schizophrenia Patients: A Prospective 8-week Longitudinal Study

BACKGROUND

Patients with antipsychotic-naïve first-episode (ANFE) schizophrenia (SZ) can help clarify many confounding factors in determining sex differences in antipsychotic drug induced weight gain and its association with symptom improvement.

METHODS

This 8-week longitudinal trial of ANFE patients with SZ enrolled 526 patients and 313 healthy controls. We evaluated bodyweight and the efficacy of antipsychotics on the Positive and Negative Syndrome Scale (PANSS) at baseline and at the end of week 8.

RESULTS

Males and females after treatment showed no sex difference in weight gain, BMI increase, and percentage of weight gain. However, at baseline, male patients had more positive symptoms than female patients, and decreases in positive symptoms, general psychopathology, and total PANSS scores were less in male than female patients. Adjusting for confounding factors using multiple linear regression confirmed that weight gain was significantly associated with these decreases in PANSS symptoms only in men not women.

CONCLUSIONS

The relationship between weight gain and symptom reduction after 8 weeks of antipsychotic treatment exists only in male patients with ANFE SZ and not in female patients.

Sex-Specific Effect of Serum Lipids and Body Mass Index on Psychotic Symptoms, a Cross-Sectional Study of First-Episode Psychosis Patients

Background: Schizophrenia is a disorder with considerable heterogeneity in course and outcomes, which is in part related to the patients' sex. Studies report a link between serum lipids, body mass index (BMI), and therapeutic response. However, the role of sex in these relationships is poorly understood. In a cross-sectional sample of first-episode psychosis (FEP) patients, we investigated if the relationship between serum lipid levels (total cholesterol, HDL-C, LDL-C, and triglycerides), BMI, and symptoms differs between the sexes. Methods: We included 435 FEP patients (males: N = 283, 65%) from the ongoing Thematically Organized Psychosis (TOP) study. Data on clinical status, antipsychotics, lifestyle, serum lipid levels, and BMI were obtained. The Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS) were used to assess psychotic and depressive symptoms. General linear models were employed to examine the relationship between metabolic variables and symptomatology. Results: We observed a female-specific association between serum HDL-C levels and negative symptoms (B = -2.24, p = 0.03) and between triglycerides levels (B = 1.48, p = 0.04) and BMI (B = 0.27, p = 0.001) with depressive symptoms. When controlling for BMI, only the association between serum HDL-C levels and negative symptoms remained significant. Moreover, the HDL-C and BMI associations remained significant after controlling for demography, lifestyle, and illness-related factors. Conclusion: We found a relationship between metabolic factors and psychiatric symptoms in FEP patients that was sex-dependent.

The thalamic midline nucleus reuniens: potential relevance for schizophrenia and epilepsy

Anatomical, electrophysiological and behavioral studies in rodents have shown that the thalamic midline nucleus reuniens (RE) is a crucial link in the communication between hippocampal formation (HIP, i.e., CA1, subiculum) and medial prefrontal cortex (mPFC), important structures for cognitive and executive functions. A common feature in neurodevelopmental and neurodegenerative brain diseases is a dysfunctional connectivity/communication between HIP and mPFC, and disturbances in the cognitive domain. Therefore, it is assumed that aberrant functioning of RE may contribute to behavioral/cognitive impairments in brain diseases characterized by cortico-thalamo-hippocampal circuit dysfunctions. In the human brain the connections of RE are largely unknown. Yet, recent studies have found important similarities in the functional connectivity of HIP-mPFC-RE in humans and rodents, making cautious extrapolating experimental findings from animal models to humans justifiable. The focus of this review is on a potential involvement of RE in schizophrenia and epilepsy.

A new sex-specific underlying mechanism for female schizophrenia: accelerated skewed X chromosome inactivation

BACKGROUND

X chromosome inactivation (XCI) is the mechanism by which the X-linked gene dosage is adjusted between the sexes. Evidence shows that many sex-specific diseases have their basis in X chromosome biology. While female schizophrenia patients often have a delayed age of disease onset and clinical phenotypes that are different from those of males, it is unknown whether the sex differences in schizophrenia are associated with X-linked gene dosage and the choice of X chromosome silencing in female cells. Previous studies demonstrated that sex chromosome aneuploidies may be related to the pathogeneses of some psychiatric diseases. Here, we examined the changes in skewed XCI in patients with schizophrenia.

METHODS

A total of 109 female schizophrenia (SCZ) patients and 80 age- and sex-matched healthy controls (CNTLs) were included in this study. We evaluated clinical features including disease onset age, disease duration, clinical symptoms by the Positive and Negative Syndrome Scale (PANSS) and antipsychotic treatment dosages. The XCI skewing patterns were analyzed by the methylation profile of the HUMARA gene found in DNA isolated from SCZ patient and CNTL leukocytes in the three age groups.

RESULTS

First, we found that the frequency of skewed XCI in SCZ patients was 4 times more than that in the age- and sex-matched CNTLs (p < 0.01). Second, we found an earlier onset of severe XCI skewing in the SCZ patients than in CNTLs. Third, we demonstrated a close relationship between the severity of skewed XCI and schizophrenic symptoms (PANSS score ≥ 90) as well as the age of disease onset. Fourth, we demonstrated that the skewed XCI in SCZ patients was not transmitted from the patients' mothers.

LIMITATIONS

The XCI skewing pattern might differ depending on tissues or organs. Although this is the first study to explore skewed XCI in SCZ, in the future, samples from different tissues or cells in SCZ patients might be important for understanding the impact of skewed XCI in this disease.

CONCLUSION

Our study, for the first time, investigated skewed XCI in female SCZ patients and presented a potential mechanism for the sex differences in SCZ. Our data also suggested that XCI might be a potential target for the development of female-specific interventions for SCZ.

Brain structural correlates of familial risk for mental illness: a meta-analysis of voxel-based morphometry studies in relatives of patients with psychotic or mood disorders

Schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD) are heritable psychiatric disorders with partially overlapping genetic liability. Shared and disorder-specific neurobiological abnormalities associated with familial risk for developing mental illnesses are largely unknown. We performed a meta-analysis of structural brain imaging studies in relatives of patients with SCZ, BD, and MDD to identify overlapping and discrete brain structural correlates of familial risk for mental disorders. Search for voxel-based morphometry studies in relatives of patients with SCZ, BD, and MDD in PubMed and Embase identified 33 studies with 2292 relatives and 2052 healthy controls (HC). Seed-based d Mapping software was used to investigate global differences in gray matter volumes between relatives as a group versus HC, and between those of each psychiatric disorder and HC. As a group, relatives exhibited gray matter abnormalities in left supramarginal gyrus, right striatum, right inferior frontal gyrus, left thalamus, bilateral insula, right cerebellum, and right superior frontal gyrus, compared with HC. Decreased right cerebellar gray matter was the only abnormality common to relatives of all three conditions. Subgroup analyses showed disorder-specific gray matter abnormalities in left thalamus and bilateral insula associated with risk for SCZ, in left supramarginal gyrus and right frontal regions with risk for BD, and in right striatum with risk for MDD. While decreased gray matter in right cerebellum might be a common brain structural abnormality associated with shared risk for SCZ, BD, and MDD, regional gray matter abnormalities in neocortex, thalamus, and striatum appear to be disorder-specific.

Characteristics of gray matter alterations in never-treated and treated chronic schizophrenia patients

Though gray matter deficits have been consistently revealed in chronic treated schizophrenia, it is still not clear whether there are different brain alterations between chronic never treated and treated patients. To explore the different patterns of gray matter alterations among chronic never treated patients and those treated with monotherapy, we recruited 35 never-treated chronic schizophrenia patients with illness durations ranging from 5 to 48 years, 20 illness duration-matched risperidone monotherapy and 20 clozapine monotherapy patients, and 55 healthy controls. GM (surface area, cortical thickness, and cortical volume) measures were extracted and compared using ANCOVA across the four groups followed by post hoc tests. Relative to controls, both treated and never-treated chronic schizophrenia patients showed reduced GM mainly involving the bilateral medial and rostral middle frontal, left banks superior temporal sulcus, left fusiform, and left pericalcarine cortex and increased in the left cuneus. Compared with the untreated patient group, the two treated groups showed reductions mainly in the bilateral prefrontal, temporal, and left inferior parietal lobules. The clozapine monotherapy patients demonstrated more severe decreases in the bilateral prefrontal cortex and left cuneus and less severe decreases in the left ventral temporal lobe than risperidone monotherapy patients. These findings provide new insights into the long-term effects of antipsychotic treatment on gray matter alterations in schizophrenia patients. Furthermore, the characteristic findings of reductions in the inferior parietal lobule might be specific for long-term antipsychotic treatment, which could be a possible target for medication development in the future.

The promises and pitfalls of sex difference research

Funding agencies in North America and Europe are recognizing the importance of the integration of sex differences into basic and clinical research. Although these mandates are in place to improve our knowledge of health for both men and women, there have been a number of implementation issues that require vigilance on the part of funders and the research community. Here we discuss issues on simple inclusion of both sexes in studies to specialisation of sex differences with attention paid to statistics and the need for sex-specific treatments. We suggest differing mandates need to be considered regarding simple integration versus the need for studies in the specialisation of sex differences and/or the need for research that recognises the importance of male-specific or female-specific factors that influence subsequent health such as menstruation, menopause or pregnancy.

Clinical and non-clinical hallucinations are similarly associated with source memory errors in a visual memory task

Hallucinations have been found to be associated with various types of source memory failure in both schizophrenia patients and hallucination-prone healthy individuals. We investigated the associations of clinical and non-clinical hallucinations with source memory errors in a visual memory task that involved the remembering of picture presentation context. 59 schizophrenia patients and 61 healthy individuals took part in the study. Pictures were presented either at different locations or in association with different visual stimuli. The participants were required afterwards to recognize the target pictures among distractors, and then to remember their spatial location or the visual stimulus that was associated with them. Liberal response bias in picture recognition was associated with hallucination proneness and auditory-verbal hallucinations in subsamples of participants with significant non-clinical or clinical hallucinations. After controlling for overall memory performance, failure to remember the spatial location of the pictures was associated with visual hallucinations in male patients; failure to remember the associated visual stimulus was related to auditory-verbal hallucinations in female patients and to hallucination proneness in healthy women. The findings suggest that both clinical and non-clinical hallucinations are associated with loss of contextual information relative to the acquisition of events.