Sex versus gender differences in schizophrenia: The case for normal personality differences

Sex, gender, and outcome in first-episode psychosis: The role of premorbid functioning

We examined the associations of sex (biological distinction) and gender (societal distinction) with psychopathology, depressive symptoms and social and occupational functioning over 24 months. We found that lower masculinity scores were associated with worse psychopathology outcomes, independent of sex and other neurodevelopmental factors. These effects were mediated by poor premorbid adjustment, which also mediated the relationship between childhood trauma and masculinity scores as predictors of disorganized symptom outcomes. Our findings highlight the importance of considering gender as a separate construct and the need for further research to understand the clinical implications of sex and gender differences in schizophrenia.

Insights into Sex and Gender Differences in Brain and Psychopathologies Using Big Data

The societal implication of sex and gender (SG) differences in brain are profound, as they influence brain development, behavior, and importantly, the presentation, prevalence, and therapeutic response to diseases. Technological advances have enabled speed up identification and characterization of SG differences during development and in psychopathologies. The main aim of this review is to elaborate on new technological advancements, such as genomics, imaging, and emerging biobanks, coupled with bioinformatics analyses of data generated from these technologies have facilitated the identification and characterization of SG differences in the human brain through development and psychopathologies. First, a brief explanation of SG concepts is provided, along with a developmental and evolutionary context. We then describe physiological SG differences in brain activity and function, and in psychopathologies identified through imaging techniques. We further provide an overview of insights into SG differences using genomics, specifically taking advantage of large cohorts and biobanks. We finally emphasize how bioinformatics analyses of big data generated by emerging technologies provides new opportunities to reduce SG disparities in health outcomes, including major challenges.

Homocysteine Levels and Clinical Outcomes in Schizophrenia—A Pilot Randomized Controlled Trial

Background:

There is an increasing need for proactive and individualized responses to various diseases in today’s progressive health-care fraternity. Accordingly, the approach to schizophrenia patients encompasses novel developments in the area of personalized medicine. Antipsychotic drugs in clinical practice necessitate biomarkers for the prediction of treatment outcomes and monitoring to ensure an appropriate choice of duration of chronic therapies. Hence, we studied the relation between homocysteine levels in peripheral blood and the effectiveness as well as the safety of haloperidol and olanzapine in schizophrenia treatment.

Materials and Methods:

A prospective randomized parallel-group open-label interventional clinical trial was conducted on 40 mild to moderate schizophrenia patients. To compare the efficacy of olanzapine and haloperidol Brief Psychiatric Rating Scale (BPRS) score was used. Homocysteine levels of peripheral blood and Abnormal Involuntary Movement Scale scores were evaluated.

Results:

BPRS score improved in both groups on day 14 and day 28. But significantly more with olanzapine ( P value =.001). The olanzapine group showed a higher reduction (13.91±0.47 to 9.74±0.5) in homocysteine levels than the haloperidol group. Also, the BPRS scores negatively correlated ( r = –0.66) to homocysteine levels.

Conclusion:

Therefore, our study shows that peripheral blood homocysteine levels can be used to predict and assess the treatment outcome in schizophrenia patients. Biomarker driven approach in schizophrenia will allow the patients to be treated promptly with the right drug. In this light, personalized treatment holds great potential in the future.

Sex and gender associations with indicators of neurodevelopmental compromise in schizophrenia spectrum disorders

BACKGROUND

It has been proposed that sex and gender differences described in schizophrenia can be explained from a neurodevelopmental perspective.

AIM

In this study, we examined the associations of biological sex and gender role endorsement with putative indicators of neurodevelopmental compromise.

METHODS

We used the Bem Sex Role Inventory to calculate masculinity scores in 77 patients with a first episode of a schizophrenia spectrum disorder, and selected the following indicators of neurodevelopmental compromise: family history of schizophrenia, obstetric complications, premorbid functioning, neurological soft signs, and cognitive function. Secondary objectives included the moderating effects of age of onset of illness, substance use and negative symptoms on these associations.

RESULTS

There were no significant sex differences across any of the indicators of neurodevelopmental compromise. However, lower masculinity scores correlated significantly with poorer premorbid adjustment, sensory integration deficits and worse overall cognitive performance. Stepwise linear regression identified poorer premorbid adjustment in early adolescence and lower verbal learning scores as independent predictors of lower masculinity scores. In contrast to sex, gender showed several associations with indicators of neurodevelopmental compromise.

CONCLUSIONS

Lower masculinity scores may represent part of a phenotype for a neurodevelopmental anomaly that places some individuals on a pathway to schizophrenia.

Gender role endorsement in first-episode schizophrenia spectrum disorders

Sex (a biological distinction) and gender (a social construct) are inter-related, but semi-independent measures. The aim of our research was to compare gender role endorsement between first-episode schizophrenia spectrum disorder patients (n=77) and matched controls (n=64). The Bem Sex Role Inventory (BSRI) was used to assess masculinity and femininity scores as separate linear measures. This well-known research instrument also allowed us to examine gender as a categorical measure based on sex-specific cut-off scores calculated for controls as our normative reference sample using a median-split technique. First, we found that both masculinity and femininity scores differed between patients and controls. The distribution of gender as a categorical measure also differed between the two groups. Post-hoc testing with correction for multiple comparisons identified masculinity scores in particular as being lower in both male and female patients compared to controls of the corresponding sex. In conclusion, lower masculinity scores reported for chronic schizophrenia also affects first-episode patients with minimal prior treatment exposure irrespective of their biological sex. Future studies would do well to examine the associations of sex and gender with clinical and treatment outcomes from the perspective of the neurodevelopmental model of schizophrenia as a proposed "disorder of the self".

Schizophrenia and the retina: Towards a 2020 perspective

BACKGROUND

Differences between people with schizophrenia and psychiatrically healthy controls have been consistently demonstrated on measures of retinal function such as electroretinography (ERG), and measures of retinal structure such as optical coherence tomography (OCT). Since our 2015 review of this literature, multiple new studies have been published using these techniques. At the same time, the accumulation of data has highlighted the "fault lines" in these fields, suggesting methodological considerations that need greater attention in future studies.

METHODS

We reviewed studies of ERG and OCT in schizophrenia, as well as data from studies whose findings are relevant to interpreting these papers, such as those on effects of the following on ERG and OCT data: comorbid medical conditions that are over-represented in schizophrenia, smoking, antipsychotic medication, substance abuse, sex and gender, obesity, attention, motivation, and influences of brain activity on retinal function.

RESULTS

Recent ERG and OCT studies continue to support the hypothesis of retinal structural and functional abnormalities in schizophrenia, and suggest that these are relevant to understanding broader aspects of pathophysiology, neurodevelopment, and neurodegeneration in this disorder. However, there are differences in findings which suggest that the effects of multiple variables on ERG and OCT data need further clarification.

CONCLUSIONS

The retina, as the only component of the CNS that can be imaged directly in live humans, has potential to clarify important aspects of schizophrenia. With greater attention to specific methodological issues, the true potential of ERG and OCT as biomarkers for important clinical phenomena in schizophrenia should become apparent.

Schizophrenia and the retina: Towards a 2020 perspective

BACKGROUND

Differences between people with schizophrenia and psychiatrically healthy controls have been consistently demonstrated on measures of retinal function such as electroretinography (ERG), and measures of retinal structure such as optical coherence tomography (OCT). Since our 2015 review of this literature, multiple new studies have been published using these techniques. At the same time, the accumulation of data has highlighted the "fault lines" in these fields, suggesting methodological considerations that need greater attention in future studies.

METHODS

We reviewed studies of ERG and OCT in schizophrenia, as well as data from studies whose findings are relevant to interpreting these papers, such as those on effects of the following on ERG and OCT data: comorbid medical conditions that are over-represented in schizophrenia, smoking, antipsychotic medication, substance abuse, sex and gender, obesity, attention, motivation, and influences of brain activity on retinal function.

RESULTS

Recent ERG and OCT studies continue to support the hypothesis of retinal structural and functional abnormalities in schizophrenia, and suggest that these are relevant to understanding broader aspects of pathophysiology, neurodevelopment, and neurodegeneration in this disorder. However, there are differences in findings which suggest that the effects of multiple variables on ERG and OCT data need further clarification.

CONCLUSIONS

The retina, as the only component of the CNS that can be imaged directly in live humans, has potential to clarify important aspects of schizophrenia. With greater attention to specific methodological issues, the true potential of ERG and OCT as biomarkers for important clinical phenomena in schizophrenia should become apparent.

Words Matter: Sex and Gender as Unique Variables in Research

Sex and gender are not equivalent concepts, even though these 2 variables are often used interchangeably by researchers. The precise use of variables is critical to ensure that research and theoretical work is of the highest quality. This article defines sex and gender and the importance of recognizing both of these variables as being unique and then demonstrates the benefit of measuring both of these variables using the cardiovascular disease literature as an exemplar. Additionally, recommendations for scholars regarding the use of sex and gender in the research and theoretical literature are provided.

Schizophrenia spectrum and other psychotic disorders

Since its earliest conceptualization, schizophrenia has been considered a disorder of "young men." Contemporary research suggests that there are sex differences in schizophrenia that are both transdiagnostic and representative of general sex/gender differences across the psychopathology spectrum. This chapter selectively summarizes representative sex/gender differences in clinical expression, epidemiology, risk factors, treatment, as well as course and outcome in schizophrenia. The consistent sex differences found, such as onset age, generic brain anomalies, and hormonal involvement, are not specific to schizophrenia or necessarily to psychopathology. It is suggested that in working with those diagnosed as meeting the current criteria for schizophrenia, clinicians adopt a transdiagnostic framework informed by sex and gender role processes.

Anti-TSNARE1 IgG plasma levels differ by sex in patients with schizophrenia in a Chinese population

It was recently reported that levels of plasma IgG antibodies against peptide antigens derived from proteins encoded by schizophrenia-associated genes are altered in individuals with schizophrenia treated with antipsychotics. This study aimed to replicate the initial finding in antipsychotic-naïve patients with first-episode schizophrenia and to explore the possible mechanism by which immune tolerance of B cells may be altered in this disease. A total of 408 case-control plasma samples were collected for analysis of circulating IgG antibodies against fragments derived from TCF4, TSNARE1, ZNF804A, TRANK1, ERCC4, DPYD and CD25 using an in-house ELISA. The Mann-Whitney U-test revealed that patients with schizophrenia had a significant change in plasma anti-TSNARE1 and anti-CD25 IgG levels; male patients mainly contributed to the increased levels of anti-TSNARE1 IgG and anti-CD25 IgG. Receiver operating characteristic (ROC) curve analysis revealed that the anti-TSNARE1 IgG assay had an area under the ROC curve of 0.625 with a sensitivity of 15.7% and a specificity of 95.2%. Work on a B-cell model revealed that TRANK1-derived antigen treatments could enhance the proportions of CD83+ cells and apoptotic B cells when compared with TSNARE1-derived antigen and vehicle treatment. We conclude that there is a gender difference in autoimmune responses in schizophrenia and suggest that anti-TSNARE1 IgG may be indicative of schizophrenia in a subgroup of male patients.

Intimate partner violence and mental disorders: Co-occurrence and gender differences in a large cross-sectional population based study in Spain

BACKGROUND

Intimate partner violence (IPV) and mental disorders (MD) are important public health problems disproportionally affecting women. We aimed to study the epidemiology of IPV victimization, MD, and co-occurring IPV-MD in Spanish men and women in terms of i) prevalence, ii) association between IPV and MD, and iii) sociodemographic and clinical characteristics associated with IPV, MD, and co-occurring IPV-MD.

METHODS

Community-based cross-sectional study with 4507 randomly selected participants. Measurement instruments (Mini International Neuropsychiatric Interview and set of validated questions about IPV during the last 12 months) were administered by trained interviewers in participants' households. Statistical analyses included multivariate logistic regression models.

RESULTS

The prevalence of IPV was 9.4%, of MD 22.3%, and of co-occurring MD-IPV 4.4%. MD was associated with higher odds of experiencing IPV (OR = 3.6; p < 0.05). Lack of social support, neuroticism, impulsivity, and family history of MD were associated with higher odds of IPV, MD, and co-occurring IPV-MD in men and women. Poor health status was associated with MD and with co-occurring IPV-MD in men and women. In women, not being married was associated with MD and with co-occurring IPV-MD; having a non-Spanish nationality was associated with IPV and co-occurring IPV-MD; and older age with IPV. In men, younger age was associated with MD.

LIMITATIONS

The cross-sectional nature of this study limited our ability to examine causal inferences.

CONCLUSIONS

MD and IPV are strongly associated. Although less frequently than in women, IPV in men is also associated with depression, post-traumatic and mood disorders, which has relevant implications for healthcare delivery.