Sex differences in schizophrenia: estrogen and mitochondria

Gender differences and clinical correlates in the age of the first hospitalization in patients with drug-naïve schizophrenia in China: a cross-sectional study

Gender differences in the onset age of schizophrenia have been reported in many studies, but differences in the age of the first hospitalization and associated factors have not been explored. The present study investigated gender differences and clinical correlates in the age of the first hospitalization in drug-naïve schizophrenia (DNS). A total of 144 DNS patients and 67 health controls were included. Demographic information, duration of untreated psychosis (DUP), Positive and Negative Symptom Scale (PANSS) scores, the Brief Psychiatric Rating Scale (BPRS) scores, Global Assessment of Functioning (GAF) scores, and MATRICS Consensus Cognitive Battery (MCCB) scores were collected and analyzed. The age of the first hospitalization was significantly earlier in males than in females (P < 0.01). In addition, there were significant differences in the age of the first hospitalization in terms of marital status, occupation, family ranking, suicide attempt, and place of residence (all P < 0.05). After Bonferroni correction, only DUP had a positive correlation with the age of the first hospitalization (PBonferroni < 0.05/6 = 0.0083). Multivariate linear regression analysis showed that gender (β = 0.141, t = 2.434, P = 0.016), marital status (β = 0.219, t = 3.463, P = 0.001), family ranking (β = 0.300, t = 4.918, P < 0.001), suicide attempt (β = 0.348, t = 5.549, P < 0.001), and DUP (β = 0.190, t = 2.969, P < 0.004) positively predicted the age of the first hospitalization. The age of the first hospitalization in male DNS was earlier than in females. In addition, gender, marital status, suicide attempt, DUP, and family rank were independent risk factors for the age of the first hospitalization.

Insights into the adverse effects of prepubertal chronic ethanol exposure on adult female reproduction

Heavy drinking in women is known to adversely affect pregnancy and fertility. However, pregnancy is a complex process, and the adverse effects of ethanol on pregnancy does not mean that ethanol will have adverse effects on all stages from gamete to fetal formation. Similarly, the adverse effects of ethanol before and after adolescence cannot be generalized. To focus on the effects of prepubertal ethanol on female reproductive ability, we established a mouse model of prepubertal ethanol exposure by changing drinking water to 20% v/v ethanol. Some routine detections were performed on the model mice, and details such as mating, fertility, reproductive organ and fetal weights were recorded day by day after discontinuation of ethanol exposure. Prepubertal ethanol exposure resulted in decreased ovarian weight and significantly reduced oocyte maturation and ovulation after sexual maturation, however, normal morphology oocytes with discharged polar body showed normal chromosomes and spindle morphology. Strikingly, oocytes with normal morphology from ethanol exposed mice showed reduced fertilization rate, but once fertilized they had the ability to develop to blastocysts. RNA-seq analysis showed that the gene expression of the ethanol exposed oocytes with normal morphology had been altered. These results show the adverse effects of prepubertal alcohol exposure on adult female reproductive health.

Sex differences in the prevalence and clinical correlates of diabetes in Chinese patients with chronic schizophrenia

Sex differences have been noted in schizophrenia (SCZ) and diabetes mellitus (DM); however, the effect of sex on SCZ patients with DM remains unknown. We aimed to investigate sex differences in the prevalence, demographic and clinical correlates of DM in Chinese patients with chronic SCZ. A total of 988 Han Chinese SCZ patients (male/female: 638/350) were recruited from two psychiatric hospitals in China. We used the Positive and Negative Syndrome Scale (PANSS) to evaluate the psychopathological symptoms of the patients. In addition, serum glucose and lipid levels were assayed. The prevalence of DM in female patients (57/350, 16.29%) was higher than that in male patients (79/638, 12.38%). Binary logistic regression analyses confirmed that the prevalence of DM in female patients was higher than that in male patients (P < 0.001, OR = 4.62, 95% CI = 2.11-10.11). Moreover, female patients had significantly higher positive symptoms than male patients (P = 0.003, OR = 1.08, 95% CI = 1.03-1.14). Further, higher body mass index (BMI) and higher triglyceride (TG) were significantly associated with DM in men (both P < 0.05). Decreased high density lipoprotein (HDL) was significantly associated with DM in both male and female patients (both P < 0.01). Comorbid DM is more common in female SCZ patients, and there are sex-specific correlates of DM in SCZ.

Prevalence and clinical correlates of impaired glucose tolerance in first-episode versus chronic patients with schizophrenia

AIM

Studies using oral glucose tolerance tests (OGTT) have shown that impaired glucose metabolism presents in the early stages of schizophrenia (SCZ). However, there is a lack of studies on changes in glucose metabolism with the stage of the disease. We first explored the features of glucose metabolic pattern at different phases of male SCZ.

METHODS

We recruited 83 male first episode drug-naïve patients with SCZ (FEDN-SCZ) and 64 male chronic patients with SCZ (CH-SCZ), as well as 14 male healthy controls. The Positive and Negative Syndrome Scale (PANSS) was used to assess the psychopathology of patients. OGTT, fasting plasma glucose and lipid profiles of all participants were examined.

RESULTS

While the impaired glucose tolerance (IGT) rate of male SCZ patients was higher than that of HC (P < .05), there was no difference in IGT prevalence between FEDN-SCZ and CH-SCZ. In male FEDN-SCZ, LDL (OR = 2.64, 95% CI = 1.11-6.29, P = .028) and PANSS total score (OR = 1.03, 95% CI = 1.00-1.06, P = .046) were positively correlated with IGT; in male CH-SCZ, BMI (OR = 1.7, 95% CI = 1.08-2.67, P = .023), PANSS total score (OR = 0.82, 95% CI = 0.70-0.96, P = .015) and positive symptoms (OR = 0.45, 95% CI = 0.20-0.99, P = .046) were significantly correlated with IGT.

CONCLUSIONS

Our findings reflect different glucose metabolism patterns in different stages of SCZ.

Sex differences in social functioning of patients with schizophrenia depending on the age of onset and severity of the disease

AIM

Schizophrenia manifests differently in women and men. This disease starts at a young age, leads to disability at working age. The aim of our work was to study sex differences, association between social factors and different parameters of the clinical picture and the course of the disease.

METHODS

This study was performed using population of Russian patients (men: 345, women: 310). Patients were examined using DSM-V, Bush-Francis catatonia rating scale (BFCRS), Positive and Negative Syndrome Scale (PANSS), 4-Items Negative Symptoms Assessment (NSA-4) and Frontal Assessment Battery (FAB).

RESULTS

Sex differences were mainly shown through negative symptoms, which were more severe in male patients. Men were shown to experience a decrease in social functioning and earlier age of onset. A positive family history further influenced negative symptoms and age of onset. When comparing scores before and after inpatient treatment (4 weeks), sex differences were not so pronounced. Female patients and patients with high levels of education, no conflictual relationship with family and active labour activity showed a later age of onset of the prodromal events and manifestation age. The decrease in the number of social contacts correlated with lower age of disability. The association between social factors and the severity of psychotic symptoms was shown across DSM-V, PANSS, NSA-4 and FAB, but not for BFCRS. Social factors were associated with negative symptoms of schizophrenia, but not with positive.

CONCLUSION

For successful treatment of patients with schizophrenia, the discussed factors must be considered and schizophrenia treatment methods should be primarily aimed at improving social functioning.

Estrogens in schizophrenia: progress, current challenges and opportunities

PURPOSE OF REVIEW

Schizophrenia is a heterogeneous psychiatric disorder with a different, but not necessarily milder clinical presentation in women as compared to men. These sex differences have largely been attributed to the protective role of estrogens. This article reviews the current state of estrogen research in schizophrenia.

RECENT FINDINGS

Estrogens regulate important pathophysiological pathways in schizophrenia, including dopamine activity, mitochondrial function, and the stress system. Estrogen deficiency is common in both sexes and is associated with increases in psychotic symptoms. Hyperprolactinemia causes secondary estrogen deficiency and can be a reaction to stress, or secondary to prolactin-raising antipsychotics. Therefore, prolactin-sparing antipsychotics should be preferred especially in premenopausal women, who are more prone to hyperprolactinemia. Premenopausal women furthermore require lower doses of antipsychotics than men, since estrogens raise the availability and efficacy of antipsychotics.

SUMMARY

The past years have established the importance of estrogens in the pathophysiology of schizophrenia and have shown its relevance to clinical practice through its influence on antipsychotic drug efficacy. Future research should focus on the neurobiological and clinical effect of contraceptives in premenopausal women with schizophrenia. Furthermore, the potential of estrogen-like augmentation with raloxifene and phytoestrogens in schizophrenia should be established in the coming years.

Beyond the Mind-Serum Trace Element Levels in Schizophrenic Patients: A Systematic Review

The alterations in serum trace element levels are common phenomena observed in patients with different psychiatric conditions such as schizophrenia, autism spectrum disorder, or major depressive disorder. The fluctuations in the trace element concentrations might act as potential diagnostic and prognostic biomarkers of many psychiatric and neurological disorders. This paper aimed to assess the alterations in serum trace element concentrations in patients with a diagnosed schizophrenia. The authors made a systematic review, extracting papers from the PubMed, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among 5009 articles identified through database searching, 59 of them were assessed for eligibility. Ultimately, 33 articles were included in the qualitative synthesis. This review includes the analysis of serum levels of the following trace elements: iron, nickel, molybdenum, phosphorus, lead, chromium, antimony, uranium, magnesium, aluminum, zinc, copper, selenium, calcium, and manganese. Currently, there is no consistency regarding serum trace element levels in schizophrenic patients. Thus, it cannot be considered as a reliable prognostic or diagnostic marker of schizophrenia. However, it can be assumed that altered concentrations of those elements are crucial regarding the onset and exaggeration of either psychotic or negative symptoms or cognitive dysfunctions.

On the origin of schizophrenia: Testing evolutionary theories in the post-genomic era

Considering the relatively high heritability of schizophrenia and the fact that it significantly reduces the reproductive fitness of affected individuals, it is not clear how the disorder is still maintained in human populations at a disproportionally high prevalence. Many theories propose that the disorder is a result of a trade-off between costs and benefits of the evolution of exclusively human adaptations. There have also been suggestions that schizophrenia risk alleles are accompanied with increase in fitness of affected persons or their relatives in both past and current social contexts. The discoveries of novel schizophrenia-related genes and the advancements in comparative genomics (especially comparisons of the human genome and the genomes of related species, such as chimpanzees and extinct hominids) have finally made certain evolutionary theories testable. In this paper, we review the current understanding of the genetics of schizophrenia, the basic principles of evolution that complement our understanding of the subject, and the latest genetic studies that examine long-standing evolutionary theories of schizophrenia using novel methodologies and data. We find that the origin of schizophrenia is complex and likely governed by different evolutionary mechanisms that are not mutually exclusive. Furthermore, the most recent evidence implies that schizophrenia cannot be comprehended as a trait that has elevated fitness in human evolutionary lineage, but has been a mildly deleterious by-product of specific patterns of the evolution of the human brain. In other words, novel findings do not support previous hypotheses stating that schizophrenia risk genes have an evolutionary advantage.