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

Sex Differences in Personality Disorder and Childhood Maltreatment of Patients with Schizophrenia

Introduction

Despite numerous studies investigating personality disorder (PD) and childhood maltreatment (CM) characteristics in individuals with schizophrenia (SZ), there remains a scarcity of research focusing on sex differences in PD and CM within large samples of SZ patients.

Methods

A total of 592 participants (257 males, 335 females) were consecutively sampled from patients diagnosed with SZ at the psychiatric and psycho-counseling clinics at Shanghai Mental Health Center. PDs were assessed using a self-reported personality diagnostic questionnaire and a structured clinical interview, while CMs were evaluated using the Chinese version of the Child Trauma Questionnaire Short Form.

Results

Male patients exhibited a prominent self-reported trait of antisocial PD (t=1.972, p=0.049), while female patients demonstrated a notable emphasis on histrionic PD traits (t=-2.057, p=0.040). Structured interviews for PD diagnoses further indicated a higher comorbidity of schizotypal (χ2=4.805, p=0.028) and schizoid (χ2=6.957, p=0.008) PDs among male patients compared to female patients. Additionally, male patients reported a higher degree (t=2.957, p=0.003) and proportion (χ2=5.277, p=0.022) of experiences of physical abuse in their self-reported CM. Logistic regression analyses highlight distinct factors: higher antisocial PD traits and physical abuse are associated with male patients, while histrionic PD traits and emotional abuse are associated with female patients.

Discussion

These findings underscore the importance of recognizing and addressing sex-specific manifestations of personality pathology and the nuanced impact of CM in the clinical management of individuals with SZ. The study advocates for tailored interventions that consider the distinct needs associated with sex differences in both personality traits and CM experiences among SZ patients.

Genetic study of the causal effect of lipid profiles on insomnia risk: a Mendelian randomization trial

OBJECTIVES

In response to the controversy surrounding observational studies of the association between lipid profiles and the risk of insomnia, the aim of this study was to analyze lipid profiles, including triglycerides (TG), apolipoprotein A-1 (ApoA-1), apolipoprotein B (ApoB) and lipoprotein A (LPA), in a European population to further assess the causal relationship between these lipid types and insomnia.

MATERIALS AND METHODS

This study explores the causal effect of lipid profiles on insomnia based on a genome-wide association study (GWAS)-derived public dataset using two-sample and multivariate Mendelian randomization (MVMR) analysis. The main MR analyses used inverse variance weighting (IVW) odds ratio (OR), and the sensitivity analyses included weighted median (WM) and MR‒Egger.

RESULTS

Both MR and MVMR showed that lowering ApoA-1 and LPA levels had causal effects on the risk of insomnia [MR: per 10 units, ApoA-1: OR: 0.7546, 95% CI: 0.6075-0.9372, P = 0.011; LPA: OR: 0.8392, 95% CI: 0.7202-0.9778, P = 0.025; MVMR: per 10 units, ApoA-1: OR: 0.7600, 95% CI: 0.6362-0.9079, P = 0.002; LPA, OR: 0.903, 95% CI: 0.8283-0.9845, P = 0.021]. There were no causal effects of TG or ApoB on insomnia (all P > 0.05). The MR‒Egger intercept test, funnel plot, and IVW methods all suggested an absence of strong directional pleiotropy, and leave-one-out permutation analysis did not detect any single single-nucleotide polymorphism that had a strong influence on the results.

CONCLUSION

Elevated levels of ApoA-1 and LPA were independently and causally associated with the risk of insomnia, suggesting that elevated ApoA-1 and LPA levels may contribute to a reduced risk of insomnia.

Alexithymia in Chinese patients with chronic schizophrenia: Prevalence, clinical correlates, and relationship with neurocognition and empathy

INTRODUCTION

Alexithymia is highly prevalent and strongly related to adverse consequences in patients with schizophrenia. However, its associated factors remain largely unexplored. The present study aimed to determine the prevalence of alexithymia and its association with sociocultural characteristics, clinical symptoms, neurocognition, and empathy in 854 Chinese patients with schizophrenia.

METHOD

Demographic information was collected through a self-designed questionnaire. Alexithymia was assessed by the Toronto Alexithymia Scale (TAS-20). We assessed clinical symptoms, neurocognition, and empathy via the following instruments: Positive and Negative Syndrome Scale, Repeatable Battery for the Assessment of Neuropsychological Status, and Interpersonal Reactivity Index. A multiple logistic regression model was conducted to determine the independent correlates of alexithymia.

RESULTS

Approximately one-third (n = 277, 32%) of patients with schizophrenia had alexithymia. Patients with alexithymia had significantly more severe negative symptoms, neurocognition, and empathy impairment than patients without alexithymia. Being male, negative symptoms, personal distress, empathic concern, and language functioning were independently associated with alexithymia.

DISCUSSION

Our findings demonstrate a high prevalence of alexithymia and its strong association with clinical symptoms, neurocognition, and empathy, which calls for timely screening and intervention for alexithymia in patients with schizophrenia. Targeting impaired language function, negative symptoms, and impaired affective empathy might help reduce alexithymia and its related negative consequences.

Adolescent sleep defects and dopaminergic hyperactivity in mice with a schizophrenia-linked Shank3 mutation

Shank3 is a shared risk gene for autism spectrum disorders and schizophrenia. Sleep defects have been characterized for autism models with Shank3 mutations; however, evidence has been lacking for the potential sleep defects caused by Shank3 mutation associated with schizophrenia and how early in development these defects may occur. Here we characterized the sleep architecture of adolescent mice carrying a schizophrenia-linked, R1117X mutation in Shank3. We further employed GRABDA dopamine sensor and fiber photometry to record dopamine release in the nucleus accumbens during sleep/wake states. Our results show that homozygous mutant R1117X mice have significantly reduced sleep in the dark phase during adolescence, altered electroencephalogram power, especially during the rapid-eye-movement sleep, and dopamine hyperactivity during sleep but not during wakefulness. Further analyses suggest that these adolescent defects in sleep architecture and dopaminergic neuromodulation tightly correlate with the social novelty preference later in adulthood and predict adult social performance during same-sex social interactions. Our results provide novel insights into the sleep phenotypes in mouse models of schizophrenia and the potential use of developmental sleep as a predictive metric for adult social symptoms. Together with recent studies in other Shank3 models, our work underscores the idea that Shank3-involved circuit disruptions may be one of the shared pathologies in certain types of schizophrenia and autism. Future research is needed to establish the causal relationship among adolescent sleep defects, dopaminergic dysregulation, and adult behavioral changes in Shank3 mutation animals and other models.

Meta-analysis of insomnia, suicide, and psychopathology in schizophrenia

PURPOSE OF REVIEW

Insomnia is common in schizophrenia. Insomnia has been associated with suicidal ideation and behavior, as well as greater severity of psychopathology, in schizophrenia. This review performs a meta-analysis of associations between insomnia, suicide, and psychopathology in patients with schizophrenia.

RECENT FINDINGS

We searched major electronic databases from inception until November 2022 for studies of insomnia, suicide, and psychopathology in patients with schizophrenia. Random effects meta-analysis calculating odds ratios (ORs, for suicide) and effect sizes (ESs, for psychopathology) and 95% confidence intervals (CIs) were performed. Ten studies met the inclusion criteria, comprising 3428 patients with schizophrenia. Insomnia was associated with a significant increased odds of suicidal ideation (OR = 1.84, 95% CI 1.28-2.65, P  < 0.01) and suicide attempt or death (OR = 5.83, 95% CI 1.61-2.96, P  < 0.01). Insomnia was also associated with total (ES = 0.16, 95% CI 0.09-0.23, P  < 0.01), positive (ES = 0.14, 95% CI 0.08-0.20, P  = 0.02), and general (ES = 0.17, 95% CI 0.08-0.27, P  < 0.01) psychopathology. In meta-regression analyses, BMI was negatively associated with suicidal ideation. Otherwise, age, sex, and study year were all unrelated to the associations.

SUMMARY

Insomnia is associated with suicide and psychopathology in schizophrenia. Formal assessment and treatment of insomnia appears relevant to the clinical care of schizophrenia.

Meta-analysis of clozapine and insomnia in schizophrenia

INTRODUCTION

Insomnia commonly occurs in schizophrenia, and insomnia is associated with suicide risk. Clozapine has anti-suicidal properties and beneficial effects on sleep. We performed a meta-analysis of insomnia in randomized controlled trials (RCTs) of patients with schizophrenia treated with clozapine. We hypothesized that compared to clozapine there is an increased odds of insomnia in patients treated with other antipsychotics.

METHODS

We systematically searched PubMed, PsycINFO, and Web of Science databases. We included RCTs, in English, with data on insomnia in patients with schizophrenia treated with clozapine versus other antipsychotics. Data were pooled using a random effects model.

RESULTS

Eight RCTs (1952 patients: 922 on clozapine and 1030 on other antipsychotics) met inclusion criteria. Patients treated with other antipsychotics versus clozapine had a significant increased odds of insomnia (22.3 % versus 12.4 %, OR = 2.20, 95 % CI = 1.64-2.94, p < 0.01). Olanzapine, quetiapine, risperidone, and ziprasidone were each associated with significant increased odds of insomnia compared to clozapine. In meta-regression analyses, clozapine dose, publication year, sex, trial duration, and study quality score were unrelated to the association; however, there was a significant association with age. The observed ORs for insomnia from RCTs were almost perfectly correlated with reported ORs from pharmacovigilance data.

CONCLUSION

Clozapine is associated with significantly less insomnia compared to other antipsychotics. Findings provide additional evidence for improvement in sleep as a potential pathway underlying clozapine's anti-suicidal properties. A greater mechanistic understanding of this association is needed.

Effects of Japanese policies and novel hypnotics on long-term prescriptions of hypnotics

AIM

The current study aimed to examine the effect of Japanese policies for appropriate hypnotics use and novel hypnotics (e.g. melatonin receptor agonist and orexin receptor antagonist [ORA]) on long-term prescriptions of hypnotics.

METHODS

This retrospective study was conducted using a large-scale health insurance claims database. Among subscribers prescribed hypnotics at least once between April 2005 and March 2021, those prescribed hypnotics for the first time after being included in the database in three periods (period 1: April 2012-March 2013; period 2: April 2016-March 2017; and period 3: April 2018-March 2019) were eligible. These were set considering the timing of the 2014 and 2018 medical fee revisions (2014 for polypharmacy of three or more hypnotics, 2018 for long-term prescription of benzodiazepine receptor agonists for >12 months). The duration of consecutive prescriptions of hypnotics over 12 months was evaluated. Factors associated with short-term prescriptions of hypnotics were also investigated.

RESULTS

In total, 186 535 participants were newly prescribed hypnotics. The mean duration of prescriptions was 2.9 months, and 9.3% of participants were prescribed hypnotics for 12 months. Prescription periods were not associated with short-term prescriptions of hypnotics. ORA use was associated with short-term prescriptions of hypnotics (adjusted hazard ratio, 1.077 [95% confidence interval, 1.035-1.120]; P < 0.001), but melatonin receptor agonist use was not.

CONCLUSION

Japanese policies had no statistically significant effect on long-term prescriptions of hypnotics. Although this study suggests initiating ORA for insomniacs as a candidate strategy to prevent long-term prescriptions of hypnotics, further research is necessary to draw conclusions.