Gender difference in the association between education and schizophrenia in Chinese adults

Investigating gender differences in quality of life and social support in patients with severe mental illnesses

BACKGROUND

Severe mental illnesses (SMIs), including schizophrenia and bipolar disorder affect patients significantly. Gender has been identified as a key factor influencing the experience of SMIs with notable disparities in prevalence, symptoms, and treatment outcomes. Additionally, the quality of life (QoL) and social support for patients with SMIs can vary based on gender.

AIMS

This study examined gender differences in QoL and social support of patients with SMIs.

METHOD

Participants include 170 outpatients with schizophrenia and bipolar disorder at Shafa Hospital (2021). QoL and social support were assessed using World Health Organization QoL (WHOQOL-BREF) questionnaire and Medical Outcomes Study Social Support Survey (MOS-SSS), respectively. Group differences were analyzed using t-test or Mann-Whitney U test, and two-way multivariate analyses of variance explored the effect of gender and disease type.

RESULTS

It was indicated that females with schizophrenia reported higher QoL than males, but the opposite was observed for bipolar disorder. Gender differences in social support were not significant among schizophrenia patients, nor between the two patient groups. However, women with bipolar disorder and multiple hospitalizations experienced lower social support and QoL compared to men. Additionally, more hospitalizations were associated with decreased QoL in both genders with schizophrenia.

CONCLUSIONS

Findings suggest the need for gender- specific interventions and support policies to enhance QoL and social support in patients with SMI.

Fatty acid desaturase 1/2 (FADS1 and FADS2), fatty acid desaturase indices, and their relationships with metabolic syndrome in female adults with first-episode schizophrenia after antipsychotic medications

OBJECTIVE

Although antipsychotics constitute the best treatment for patients with schizophrenia, this treatment class carries a high risk of metabolic disarrangements thus developing metabolic syndrome (MetS). Altered fatty acid (FA) composition and desaturase indices have been associated with several metabolic diseases, including MetS. Herein, we determined fatty acid desaturase 1 (FADS1) and FADS2 gene expressions, serum delta-5 desaturase (D5D) and D6D indices in female adults with first-episode schizophrenia after olanzapine medication, as well as their relationship with the incidence of MetS.

METHODS

This study prospectively recruited 120 female patients with first-episode schizophrenia who completed 6-month olanzapine medication. Among these female patients, 31 patients developed MetS and 89 patients did not.

RESULTS

The mRNA expression levels of FADS1 and FADS2 in patients were analyzed according to the presence of MetS and evaluation times with results of two-way ANOVAs (FADS1: PMetS = 0.0006, Ptime = 0.004, Pinteraction = 0.010; FADS2: PMetS = 0.012, Ptime < 0.0001, Pinteraction = 0.001). The D5D and D6D indices in patients were analyzed according to the presence of MetS and evaluation times with results of two-way ANOVAs (D5D: PMetS = 0.002, Ptime = 0.009, Pinteraction = 0.014; D6D: PMetS = 0.011, Ptime = 0.006, Pinteraction = 0.0001). The SCD-16 and SCD-18 indices in patients were analyzed according to the presence of MetS and evaluation times (SCD-16: PMetS = 0.005, Ptime = 0.009, Pinteraction = 0.016; SCD-18: PMetS = 0.037, Ptime = 0.382, Pinteraction = 0.163). The following multiple comparisons test showed the MetS exhibited reduced FADS1 mRNA expression and D5D index, increased FADS2 mRNA expression and D6D index, concomitant with an enhanced SCD-16 index, compared to the non-MetS did not after 6-month olanzapine medication.

CONCLUSION

The study suggests changes of FADS1, FADS2 expressions, and fatty acid desaturase indices including D5D, D6D, and SCD-16 may be associated with the development of MetS in female adults with first-episode schizophrenia after olanzapine medication.

Exploring the influences of education, intelligence and income on mental disorders

Background

Previous studies have shown that educational attainment (EA), intelligence and income are key factors associated with mental disorders. However, the direct effects of each factor on major mental disorders are unclear.

Aims

We aimed to evaluate the overall and independent causal effects of the three psychosocial factors on common mental disorders.

Methods

Using genome-wide association study summary datasets, we performed Mendelian randomisation (MR) and multivariable MR (MVMR) analyses to assess potential associations between the 3 factors (EA, N=766 345; household income, N=392 422; intelligence, N=146 808) and 13 common mental disorders, with sample sizes ranging from 9907 to 807 553. Inverse-variance weighting was employed as the main method in the MR analysis.

Results

Our MR analysis showed that (1) higher EA was a protective factor for eight mental disorders but contributed to anorexia nervosa, obsessive-compulsive disorder (OCD), bipolar disorder (BD) and autism spectrum disorder (ASD); (2) higher intelligence was a protective factor for five mental disorders but a risk factor for OCD and ASD; (3) higher household income protected against 10 mental disorders but confers risk for anorexia nervosa. Our MVMR analysis showed that (1) higher EA was a direct protective factor for attention-deficit/hyperactivity disorder (ADHD) and insomnia but a direct risk factor for schizophrenia, BD and ASD; (2) higher intelligence was a direct protective factor for schizophrenia but a direct risk factor for major depressive disorder (MDD) and ASD; (3) higher income was a direct protective factor for seven mental disorders, including schizophrenia, BD, MDD, ASD, post-traumatic stress disorder, ADHD and anxiety disorder.

Conclusions

Our study reveals that education, intelligence and income intertwine with each other. For each factor, its independent effects on mental disorders present a more complex picture than its overall effects.

Identifying causal associations between women's reproductive traits and risk of schizophrenia: a multivariate validated two-sample Mendelian randomization analysis

BACKGROUND

A significant association between women's reproductive traits and the risk of schizophrenia (SCZ) has been discovered, but the causalities remain unclear. We designed a two-sample univariate Mendelian randomization (MR) study using female-specific SNPs collected from a large-scale genome-wide association study as a genetic tool to explore the causal effect of female reproductive traits on the risk of SCZ, and conducted a multivariate MR study to re-validate the above findings.

METHODS

From extensive genome-wide association studies (GWAS) of people with European ancestry (n = 176,881 to 418,758 individuals), summary-level data on five female reproductive variables were extracted. Summary-level information on SCZ was taken from a GWAS meta-analysis involving 320,404 people with European ancestry. The inverse variance weighting estimations for both univariable MR (UVMR) and multivariable MR (MVMR) were presented as the primary results. MR-Egger, weighted median, simple mode, and weighted mode regression methods for UVMR, and MVMR-Egger, MVMR-Lasso, and MVMR-median methods for MVMR were used for sensitivity analyses.

RESULTS

The UVMR produced compelling proof for a connection between genetically predicted later age at first sexual intercourse (AFS) (OR, 0.632; 95% CI, 0.512-0.777; P < 0.01) and decreased SCZ risk. Pleiotropy analysis of the AFS-SCZ association confirmed the robustness of the MR results (P > 0.05). Consistent, substantial causal effects of AFS (OR, 0.592; 95%CI, 0.407-0.862; P < 0.01) on the risk of SCZ were demonstrated after adjusting for body mass index, years of schooling, and smoking initiation using MVMR.

CONCLUSIONS

Our findings provide convincing evidence that early AFS is a risk factor for SCZ. SCZ risk may be decreased by raising awareness of reproductive healthcare for women.

Does college education reduce the risk of schizophrenia? Evidence from a college enrollment expansion policy in China

BACKGROUND

Schizophrenia occurs worldwide, and the health, and economic burden is substantial. As one of the common proxies of socioeconomic status (SES), education was reported to be associated with the risk of developing schizophrenia. However, there is no causal evidence about the relationship. This paper explores the health benefits of college education for schizophrenia.

METHOD

Based on exogenous variation in college enrollment across regions and cohorts induced by college enrollment expansion policy, we use instrument variable (IV) estimate strategy to estimate impacts of college education on the risk of schizophrenia with the data from Second National Sample Survey on Disability.

RESULTS

We find that college education reduces the risk of developing schizophrenia by 4.2 percentage points. Some further analyses suggest the causal protective effect is only found among men, rural, and low-income individuals.

CONCLUSIONS

These findings provide new evidence for the causal relationship between college education and schizophrenia, and add to the literature on the health benefits of education.

IL-10 (-1082 G/A) polymorphism in Bataknese with schizophrenia

Objectives

Three biallelic polymorphisms at the promoter region of the interleukin-10 (IL-10) gene have been associated with susceptibility to schizophrenia. The aim of this case-control study was to investigate the association between IL-10 (-1082) G/A gene polymorphisms and schizophrenia among Bataknese, a native tribe inhabiting the North Sumatera province in Indonesia.

Methods

A total of 194 unrelated participants (n = 97 for each case and control groups) participated in this study. Polymerase chain reaction restriction fragment length polymorphism molecular genotyping was conducted to assess the genotype and allele distribution of IL-10 (-1082 G/A).

Results

Allele variations indicated that the dominant allele in the Batak tribe was allele A, whereas homozygous GG genotypes were not found in either group. The A allele and AA genotype were found to be risk factors for developing schizophrenia (OR = 2.26, 95% CI = 1.1825-4.3559 and OR = 2.56, 95% CI = 1.280-5.152, respectively).

Conclusion

Only the A allele and AA genotype of the IL-10 gene polymorphism at -1082 G/A contribute to schizophrenia susceptibility in Bataknese.

Correlation analysis and gender differences of cognitive function based on mini-mental state examination (MMSE) and suicidal tendency in patients with schizophrenia

BACKGROUND

The aim of this study was to investigate the correlation and gender differences between cognition and suicidal tendency in patients with schizophrenia.

METHODS

A total of 554 patients with schizophrenia were recruited. The Mini-Mental State Examination (MMSE), Positive and Negative Syndrome Scale (PANSS), Interpersonal Reactivity Index (IRI), Toronto Alexithymia Scale (TAS), and Insomnia Severity Index (ISI) were used to assess clinical symptoms.

RESULTS

In male patients, MMSE score and the incidence of suicidal tendency were correlated (P = 0.04, OR = 1.06, 95%CI: 1.00-1.12). Among patients with cognitive dysfunction, IRI score (P = 0.01, OR = 1.04, 95%CI: 1.01-1.06), and types of antipsychotic drugs (P < 0.01, OR = 3.97, 95%CI: 1.76-8.97) in male patients were associated risk factors for suicidal ideation. Among patients without cognitive dysfunction, PANSS positive subscale score (P = 0.03, OR = 1.06, 95%CI: 1.01-1.11), and PANSS general psychopathology score (P = 0.02, OR = 1.05, 95%CI: 1.01-1.08) were associated risk factors for suicidal ideation in male patients and PANSS positive subscale score (P < 0.01, OR = 1.15, 95%CI: 1.05-1.26) were associated risk factors for suicidal ideation in female patients.

CONCLUSIONS

There were significant gender differences in the correlation between cognitive functioning and suicidal ideation in patients with schizophrenia. Cognitive function may play an important mediating role in other factors on suicide.

Incidence, prevalence, and mortality of schizophrenia from 2016 to 2020 in Shandong, China

The epidemiology of schizophrenia has been reported in many countries. However, due to the limitations of those studies, the findings cannot be generalized to other parts of the world, especially in China. In this study, the incidence, prevalence, and mortality of schizophrenia in Shandong, China were calculated using data from the National Severe Mental Disorder Registration System collected between 2016 and 2020 and census data from 2010 to 2020. The overall incidence decreased from 9.61 per 100,000 in 2016 to 4.40 per 100,000 in 2020, the aggregate prevalence was approximately 3.20 per 1000, and the overall mortality ranged from 6.17 per 100,000 to 7.71 per 100,000. The evidence from this study indicated that the incidence, prevalence, and mortality of schizophrenia were higher in rural areas than in urban areas. Females had higher incidence, prevalence, and mortality than males. This study provided epidemiological information on schizophrenia and opened avenues for future research.

Patterns and correlates of insight among patients with schizophrenia in China：A network perspective

OBJECTIVE

To explore the patterns and correlates of insight among patients with schizophrenia in a large Chinese population.

METHOD

A multi-center cross-sectional study was conducted in Guangdong province, China. Patients with schizophrenia were included. Basic socio-demographic and clinical characteristics were collected in this study. Univariate analyses, multivariate logistic regression, and network analysis were conducted.

RESULTS

A total of 6090 participants (58.8% were male, and 41.2% were female) met the study criteria and completed all the assessments. 63.5% (n = 3869) patients with schizophrenia had impaired insight. Fewer drug sides effect, higher psychological and environment domains scores in quality of life have a positive significant impact on insight in patients with schizophrenia. Younger age, higher BPRS scores have a negative significant impact on insight in patients with schizophrenia. The node ITAQ 8 (strength=1.17) was the most central node within the ITAQ network, while node ITAQ 3 was the least central node (strength=0.69). The edge ITAQ 1-ITAQ 2 was the thickest and most saturated edge in network model.

CONCLUSIONS

Considering patterns and correlation of insight, it is necessary to ensure adherence to medications and engagement with mental health services for patients with schizophrenia, which could also improve their quality of life. Taking medication actively is more central to identify ITAQ and might be the potential targets for future interventions.

Cognitive reserve profiles are associated with outcome in schizophrenia

Cognitive reserve (CR), the brain's ability to cope with brain pathology to minimize symptoms, could explain the heterogeneity of outcomes in neuropsychiatric disorders, however it is still rarely investigated in schizophrenia. Indeed, this study aims to classify CR in this disorder and evaluate its impact on neurocognitive and socio-cognitive performance and daily functioning. A group of 106 patients diagnosed with schizophrenia was enrolled and assessed in these aereas: neurocognition, Theory of Mind (ToM) and daily functioning. A composite CR score was determined through an integration of the intelligence quotient and education and leisure activities. CR profiles were classified with a two-step cluster analysis and differences among clusters were determined with an analysis of variance (ANOVA). The cluster analysis was identified with three CR profiles characterized, respectively, by high, medium and low CR. ANOVA analysis showed significant differences on neurocognition, ToM and daily functioning between the clusters: people with higher CR reached significantly superior scores. This study suggests that greater general cognitive resources could act as a buffer against the effect of brain pathology, allowing patients to have a better cognitive performance, social outcome and quality of life.

Descriptive study of cases of schizophrenia in the Malian population

BACKGROUND

Schizophrenia is a relatively common disease worldwide with a point prevalence of around 5/1000 in the population. The aim of this present work was to assess the demographic, clinical, familial, and environmental factors associated with schizophrenia in Mali.

METHODS

This was a prospective descriptive study on a series of 164 patients aged at least 12 years who came for a follow-up consultation at the psychiatry department of the University Hospital Center (CHU) Point G in Mali between February 2019 and January 2020 for schizophrenia spectrum disorder as defined by DSM-5 diagnostic criteria.

RESULTS

Our results revealed that the male sex was predominant (80.5%). The 25-34 age group was more represented with 44.5%. The place of birth for the majority of our patients was the urban area (52.4%), which also represented the place of the first year of life for the majority of our patients (56.1%). We noted that the unemployed and single people accounted for 56.1 and 61% respectively. More than half of our patients 58.5% reported having reached secondary school level. With the exception of education level, there was a statistically significant difference in the distribution of demographic parameters. Familial schizophrenia cases accounted for 51.7% versus 49.3% for non-familial cases. The different clinical forms were represented by the paranoid form, followed by the undifferentiated form, and the hebephrenic form with respectively 34, 28 and 17.1%. We noted that almost half (48.8%) of patients were born during the cold season. Cannabis use history was not observed in 68.7% of the patients. The proportions of patients with an out-of-school father or an out-of-school mother were 51.2 and 64.2%, respectively.

CONCLUSION

The onset of schizophrenia in the Malian population has been associated with socio-demographic, clinical, genetic and environmental characteristics.

Gender Differences of Schizophrenia Patients With and Without Depressive Symptoms in Clinical Characteristics

Objectives: To investigate the differences in psychotic symptoms and cognitive function in schizophrenics with and without depression and to compare gender differences in the correlation between depressive symptoms and clinical characteristics in those patients. Methods: A total of 190 schizophrenia patients and 200 healthy controls were recruited in the study. We used the Positive and Negative Symptom Scale (PANSS), the Calgary Depression Scale for Schizophrenia (CDSS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to evaluate the psychiatric symptoms, depressive symptoms and cognitive function, respectively. Patients with CDSS score ≥7 were divided into depression group, and CDSS < 7 was viewed as without depression. Results: Patients with schizophrenia had lower total scores of RBANS and five subscale (immediate memory, visual span, verbal function, attention, and delayed memory) scores compared to healthy controls. In the case group, patients who concomitant with depression had higher PANSS scores (Ps < 0.001) and lower RBANS (Ps < 0.05) scores than those without depression. After gender stratification, PANSS total scores and subscale scores were significantly different between schizophrenics with and without depressive symptoms in both male and female groups (Ps < 0.001). For cognitive function, there were significant differences in RBANS total score and subscale scores except attention between female patients with and without schizophrenia but not in male schizophrenia patients. Furthermore, the correlation analysis showed that the total CDSS score was positively correlated with PANSS score (P < 0.001) and RBANS score in male and female groups (male: P = 0.010, female: P = 0.001). Conclusion: Our findings provided evidence supporting the gender differences in psychiatric symptoms and cognitive function between schizophrenia patients with and without depressive symptoms.