Meta-analytic approaches to determine gender differences in the age-incidence characteristics of schizophrenia and related psychoses

Queuosine-tRNA promotes sex-dependent learning and memory formation by maintaining codon-biased translation elongation speed

Queuosine (Q) is a modified nucleoside at the wobble position of specific tRNAs. In mammals, queuosinylation is facilitated by queuine uptake from the gut microbiota and is introduced into tRNA by the QTRT1-QTRT2 enzyme complex. By establishing a Qtrt1 knockout mouse model, we discovered that the loss of Q-tRNA leads to learning and memory deficits. Ribo-Seq analysis in the hippocampus of Qtrt1-deficient mice revealed not only stalling of ribosomes on Q-decoded codons, but also a global imbalance in translation elongation speed between codons that engage in weak and strong interactions with their cognate anticodons. While Q-dependent molecular and behavioral phenotypes were identified in both sexes, female mice were affected more severely than males. Proteomics analysis confirmed deregulation of synaptogenesis and neuronal morphology. Together, our findings provide a link between tRNA modification and brain functions and reveal an unexpected role of protein synthesis in sex-dependent cognitive performance.

The Sexual Dimorphic Synapse: From Spine Density to Molecular Composition

A synaptic sexual dimorphism is relevant in the context of multiple neurodevelopmental, neurodegenerative, and neuropsychiatric disorders. Many of these disorders show a different prevalence and progression in woman and man. A similar variance is also present in corresponding animal models. To understand and characterize this dimorphism in pathologies it is important to first understand sex differences in unaffected individuals. Therefore, sexual differences have been studied since 1788, first focusing on brain weight, size, and volume. But as these measures are not directly related to brain function, the investigation of sexual dimorphism also expanded to other organizational levels of the brain. This review is focused on sexual dimorphism at the synaptic level, as these specialized structures are the smallest functional units of the brain, determining cell communication, connectivity, and plasticity. Multiple differences between males and females can be found on the levels of spine density, synaptic morphology, and molecular synapse composition. These differences support the importance of sex-disaggregated data. The specificity of changes to a particular brain region or circuit might support the idea of a mosaic brain, in which each tile individually lies on a continuum from masculinization to feminization. Moreover, synapses can be seen as the smallest tiles of the mosaic determining the classification of larger areas.

Stratification by Sex and Hormone Level When Contrasting Men and Women in Schizophrenia Trials Will Improve Personalized Treatment

BACKGROUND

Sex and gender differences have been reported in the prevalence, expression, treatment response, and outcome of schizophrenia, but most reports are based on relatively small samples that have not been stratified for the impact of sex hormone levels. This literature review aims to show how women's hormone levels can impact the results of male/female comparisons.

METHODS

This is a narrative review of data from publications of the last decade.

RESULTS

Epidemiologic evidence, reports of the impact of hormones on cognition, results of sexually dimorphic responses to treatment, and male/female trajectories of illness over time all suggest that female hormone fluctuations exert major effects on male/female differences in schizophrenia.

CONCLUSIONS

Information on hormonal status in women participants is rarely available in clinical studies in schizophrenia, which makes male/female comparisons largely uninterpretable. These are the current challenges. Opportunities for individualized treatment are growing, however, and will undoubtedly result in improved outcomes for both women and men in the future.

Demographic, clinical and social characteristics of forensic patients diagnosed with schizophrenia at the Free State Psychiatric Complex, Bloemfontein, South Africa

Schizophrenia, prevalent in forensic mental health settings, is chronic and devastating, with a generally unfavourable course and prognosis. The aim of this study was to determine the demographic, clinical and social characteristics of forensic patients diagnosed with schizophrenia at the Free State Psychiatric Complex. A data collection form was used to gather information from the clinical records of patients diagnosed with schizophrenia between 1 January 2011 and 31 December 2015. The majority of the 110 participants were young male adults aged between 18 and 35 years with a low educational level. Cognitive impairment and positive symptoms were the most prominent clinical features. Aggressive and violent behaviour was notably prevalent. The majority of our sample had committed crimes against humans, while fewer had committed other types of crimes. It was concluded that causal factors included young adulthood, male gender, substance abuse, a poor social support system and lower educational level.

Age effects on basic symptoms in the community: A route to gain new insight into the neurodevelopment of psychosis?

Reports of limited clinical significance of attenuated psychotic symptoms before age 15/16 indicate an important role of neurodevelopment in the early detection of psychoses. Therefore, we examined if age also exerts an influence on the prevalence and clinical significance of the 14 cognitive and perceptive basic symptoms (BS) used in psychosis-risk criteria and conceptualized as the most direct self-experienced expression of neurobiological aberrations. A random representative general population sample of the Swiss canton Bern (N = 689, age 8-40 years, 06/2011-05/2014) was interviewed for BS, psychosocial functioning, and current mental disorder. BS were reported by 18% of participants, mainly cognitive BS (15%). In regression analyses, age affected perceptive and cognitive BS differently, indicating an age threshold for perceptive BS in late adolescence (around age 18) and for cognitive BS in young adulthood (early twenties)-with higher prevalence, but a lesser association with functional deficits and the presence of mental disorder in the below-threshold groups. Thereby, interaction effects between age and BS on functioning and mental disorder were commonly stronger than individual effects of age and BS. Indicating support of the proposed "substrate-closeness" of BS, differential age effects of perceptual and cognitive BS seem to follow normal brain maturation processes, in which they might occur as infrequent and temporary non-pathological disturbances. Their persistence or occurrence after conclusion of main brain maturation processes, however, might signify aberrant maturation or neurodegenerative processes. Thus, BS might provide important insight into the pathogenesis of psychosis and into differential neuroprotective or anti-inflammatory targets.

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.

The Incidence of Nonaffective, Nonorganic Psychotic Disorders in Older People: A Population-based Cohort Study of 3 Million People in Sweden

BACKGROUND

There are limited data on the epidemiology of very late-onset schizophrenia-like psychosis (VLOSLP) and how this relates to potential risk factors including migration, sensory impairment, traumatic life events, and social isolation.

METHODS

We followed up a cohort of 3 007 378 people living in Sweden, born 1920-1949, from their 60th birthday (earliest: January 15, 1980) until December 30 2011, emigration, death, or first recorded diagnosis of nonaffective psychosis. We examined VLOSLP incidence by age, sex, region of origin, income, partner or child death, birth period, and sensory impairments.

RESULTS

We identified 14 977 cases and an overall incidence of 37.7 per 100 000 person-years at-risk (95% CI = 37.1-38.3), with evidence that rates increased more sharply with age for women (likelihood ratio test: χ2(6) = 31.56, P < .001). After adjustment for confounders, rates of VLOSLP were higher among migrants from Africa (hazard ratio [HR] = 2.0, 95% CI = 1.4-2.7), North America (HR = 1.4, 95% CI = 1.0-1.9, P = .04), Europe (HR = 1.3, 95% CI = 1.2-1.4), Russian-Baltic regions (HR = 1.6, 95% CI = 1.4-1.9), and Finland (HR = 1.6, 95% CI = 1.5-1.7). VLOSLP risk was highest for those in the lowest income quartile (HR = 3.1, 95% CI = 2.9-3.3). Rates were raised in those whose partner died 2 years before cohort exit (HR = 1.1, 95% CI = 1.0-1.3, P = .02) or whose child died in infancy (HR = 1.2, 95% CI = 1.0-1.4, P = .05), those without a partner (HR = 1.9, 95% CI = 1.8-1.9) or children (HR = 2.4, 95% CI = 2.3-2.5), and those whose child had a psychotic disorder (HR = 2.4, 95% CI = 2.2-2.6).

INTERPRETATION

We identified a substantial burden of psychosis incidence in old age, with a higher preponderance in women and most migrant groups. Life course exposure to environmental factors including markers of deprivation, isolation, and adversity were associated with VLOSLP risk.

Concurrent Medial Prefrontal Cortex and Dorsal Hippocampal Activity Is Required for Estradiol-Mediated Effects on Object Memory and Spatial Memory Consolidation

Highlighted Research Paper:Chemogenetic Suppression of Medial Prefrontal-Dorsal Hippocampal Interactions Prevents Estrogenic Enhancement of Memory Consolidation in Female Mice by, Jennifer J. Tuscher, Lisa R. Taxier, Jayson C. Schalk, Jacqueline M. Haertel, and Karyn M. Frick.

The impact of gender and childhood abuse on age of psychosis onset, psychopathology and needs for care in psychosis patients

Gender is associated with several features of psychotic disorders, including age of illness onset, symptomatology, a higher prevalence of history of childhood sexual abuse (CSA) and needs for care. Childhood sexual abuse is associated with adverse mental health consequences but as there is a gender difference in stress reactivity, there may be a differential impact of CSA on psychopathology, age of psychosis onset and needs for care in First Episode Psychosis (FEP) patients. We hypothesized that a history of abuse would be associated with lowering of age of onset, increased symptomatology and more unmet needs in women but not men. A total of 444 FEP patients have been recruited within the context of the GET UP trial. Symptomatology has been assessed using the PANSS scale, needs for care with the CAN scale and childhood abuse with the CECA-Q scale. Childhood sexual abuse was more frequent among female patients [22.6% in women vs 11.6% in men (OR = 0.45, p < 0.01)], whereas there was no gender difference in the prevalence of childhood physical abuse (29.0% in women vs 31.7% in men). Childhood abuse was associated with higher levels of negative symptoms in both men and women, with a reduced age of onset in women only and little increase in needs for care in both men and women. Our results seem to suggest that childhood sexual abuse in female FEP patients may be linked to a more severe form of psychosis whose presentation is characterized by earlier age of onset and higher levels of negative symptoms and we can also speculate that gender-specific protective factors in women, but not in men, may be outweighed by the consequences of childhood abuse.

Adjunctive raloxifene for postmenopausal women with schizophrenia: A meta-analysis of randomized, double-blind, placebo-controlled trials

OBJECTIVE

Raloxifene, a selective estrogen receptor modulator, has been used in treating postmenopausal women with schizophrenia with inconsistent results. This meta-analysis of randomized, double-blind, placebo-controlled trials (RCTs) examined its efficacy and safety for postmenopausal women with schizophrenia.

METHOD

Standardized mean differences (SMDs) and risk ratio (RR) together with their 95% confidence intervals (CIs) were calculated using the random effects model.

RESULTS

The meta-analysis included 5 RCTs (n = 240) comparing raloxifene (n = 125, 60 or 120 mg/day) with placebo (n = 115). Adjunctive raloxifene outperformed placebo with regard to the Positive and Negative Syndrome Scale (PANSS) total psychopathology [n = 240, SMD:-0.64 (95%CI:-0.90, -0.37), P < 0.00001; I² = 0%], positive symptoms [n = 240, SMD:-0.49 (95%CI:-0.81, -0.16), P = 0.003; I² = 29%], negative symptoms [n = 240, SMD:-0.43 (95%CI:-0.68, -0.17), P = 0.001; I² = 0%], and general psychopathology scores [n = 240, SMD:-0.66 (95%CI:-0.92, -0.39), P < 0.00001; I² = 0%]. Both groups had similar rates of adverse events and discontinuation (n = 159, RR: 1.32 (95%CI: 0.65, 2.70), P = 0.44, I² = 0%).

CONCLUSION

Adjunctive raloxifene appears to be effective and safe in improving psychotic symptoms for postmenopausal women with schizophrenia. Review registration: CRD 42017059946.

Relationship between muscarinic M1 receptor binding and cognition in medication-free subjects with psychosis

Background

It is still unclear which underlying mechanisms are involved in cognitive deficits of psychotic disorders. Pro-cognitive effects of muscarinic M1 receptor agonists suggest alterations in M1 receptor functioning may modulate these symptoms. Post mortem studies in patients with schizophrenia have shown significantly reduced M1 receptor expression rates in the dorsolateral prefrontal cortex (DLPFC) compared to controls. To date no in-vivo examinations of M1 receptor binding in relation to cognitive impairments have been done. As cognitive deficits have similar course and prognostic relevance across psychotic disorders, the current study assessed M1 receptor binding in the DLPFC and hippocampus in relation to cognitive functioning.

Methods

Muscarinic M1 receptor binding potential (BPND) was measured using 123I-IDEX, single photon emission computed tomography (SPECT) in 30 medication-free subjects diagnosed with a psychotic disorder. A computerized neuropsychological test battery was used to assess cognition, and the positive and negative syndrome scale (PANSS) to assess severity of psychotic symptoms.

Results

Assessment of cognitive domains showed that lower M1 BPND in the DLPFC was related to overall lower performance in verbal learning and memory. In addition, lower M1 BPND in the DLPFC was related to greater negative symptom severity. Lastly, lower M1 BPND in the hippocampus was related to worse delayed recognition of verbal memory.

Conclusion

This is the first study to show that variation in M1 receptors in the DLPFC is related to cognitive and negative symptom outcome in psychotic disorders. The M1 receptor may be an important biomarker in biological stratification of patients with psychotic disorders.

What causes psychosis? An umbrella review of risk and protective factors

Psychosis is a heterogeneous psychiatric condition for which a multitude of risk and protective factors have been suggested. This umbrella review aimed to classify the strength of evidence for the associations between each factor and psychotic disorders whilst controlling for several biases. The Web of Knowledge database was searched to identify systematic reviews and meta-analyses of observational studies which examined associations between socio-demographic, parental, perinatal, later factors or antecedents and psychotic disorders, and which included a comparison group of healthy controls, published from 1965 to January 31, 2017. The literature search and data extraction followed PRISMA and MOOSE guidelines. The association between each factor and ICD or DSM diagnoses of non-organic psychotic disorders was graded into convincing, highly suggestive, suggestive, weak, or non-significant according to a standardized classification based on: number of psychotic cases, random-effects p value, largest study 95% confidence interval, heterogeneity between studies, 95% prediction interval, small study effect, and excess significance bias. In order to assess evidence for temporality of association, we also conducted sensitivity analyses restricted to data from prospective studies. Fifty-five meta-analyses or systematic reviews were included in the umbrella review, corresponding to 683 individual studies and 170 putative risk or protective factors for psychotic disorders. Only the ultra-high-risk state for psychosis (odds ratio, OR=9.32, 95% CI: 4.91-17.72) and Black-Caribbean ethnicity in England (OR=4.87, 95% CI: 3.96-6.00) showed convincing evidence of association. Six factors were highly suggestive (ethnic minority in low ethnic density area, second generation immigrants, trait anhedonia, premorbid IQ, minor physical anomalies, and olfactory identification ability), and nine were suggestive (urbanicity, ethnic minority in high ethnic density area, first generation immigrants, North-African immigrants in Europe, winter/spring season of birth in Northern hemisphere, childhood social withdrawal, childhood trauma, Toxoplasma gondii IgG, and non-right handedness). When only prospective studies were considered, the evidence was convincing for ultra-high-risk state and suggestive for urbanicity only. In summary, this umbrella review found several factors to be associated with psychotic disorders with different levels of evidence. These risk or protective factors represent a starting point for further etiopathological research and for the improvement of the prediction of psychosis.

Sex differences in the brain: Implications for behavioral and biomedical research

Biological differences between males and females are found at multiple levels. However, females have too often been under-represented in behavioral neuroscience research, which has stymied the study of potential sex differences in neurobiology and behavior. This review focuses on the study of sex differences in the neurobiology of social behavior, memory, emotions, and recovery from brain injury, with particular emphasis on the role of estrogens in regulating forebrain function. This work, presented by the authors at the 2016 meeting of the International Behavioral Neuroscience Society, emphasizes varying approaches from several mammalian species in which sex differences have not only been documented, but also become the focus of efforts to understand the mechanistic basis underlying them. This information may provide readers with useful experimental tools to successfully address recently introduced regulations by granting agencies that either require (e.g. the National Institutes of Health in the United States and the Canadian Institutes of Health Research in Canada) or recommend (e.g. Horizon 2020 in Europe) the inclusion of both sexes in biomedical research.

Treated Incidence of Psychotic Disorders in the Multinational EU-GEI Study

Importance

Psychotic disorders contribute significantly to the global disease burden, yet the latest international incidence study of psychotic disorders was conducted in the 1980s.

Objectives

To estimate the incidence of psychotic disorders using comparable methods across 17 catchment areas in 6 countries and to examine the variance between catchment areas by putative environmental risk factors.

Design, Setting, and Participants

An international multisite incidence study (the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions) was conducted from May 1, 2010, to April 1, 2015, among 2774 individuals from England (2 catchment areas), France (3 catchment areas), Italy (3 catchment areas), the Netherlands (2 catchment areas), Spain (6 catchment areas), and Brazil (1 catchment area) with a first episode of nonorganic psychotic disorders (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] codes F20-F33) confirmed by the Operational Criteria Checklist. Denominator populations were estimated using official national statistics.

Exposures

Age, sex, and racial/ethnic minority status were treated as a priori confounders. Latitude, population density, percentage unemployment, owner-occupied housing, and single-person households were treated as catchment area-level exposures.

Main Outcomes and Measures

Incidence of nonorganic psychotic disorders (ICD-10 codes F20-F33), nonaffective psychoses (ICD-10 codes F20-F29), and affective psychoses (ICD-10 codes F30-F33) confirmed by the Operational Criteria Checklist.

Results

A total of 2774 patients (1196 women and 1578 men; median age, 30.5 years [interquartile range, 23.0-41.0 years]) with incident cases of psychotic disorders were identified during 12.9 million person-years at risk (crude incidence, 21.4 per 100 000 person-years; 95% CI, 19.4-23.4 per 100 000 person-years). A total of 2183 patients (78.7%) had nonaffective psychotic disorders. After direct standardization for age, sex, and racial/ethnic minority status, an 8-fold variation was seen in the incidence of all psychotic disorders, from 6.0 (95% CI, 3.5-8.6) per 100 000 person-years in Santiago, Spain, to 46.1 (95% CI, 37.3-55.0) per 100 000 person-years in Paris, France. Rates were elevated in racial/ethnic minority groups (incidence rate ratio, 1.6; 95% CI, 1.5-1.7), were highest for men 18 to 24 years of age, and were lower in catchment areas with more owner-occupied homes (incidence rate ratio, 0.8; 95% CI, 0.7-0.8). Similar patterns were observed for nonaffective psychoses; a lower incidence of affective psychoses was associated with higher area-level unemployment (incidence rate ratio, 0.3; 95% CI, 0.2-0.5).

Conclusions and Relevance

This study confirmed marked heterogeneity in risk for psychotic disorders by person and place, including higher rates in younger men, racial/ethnic minorities, and areas characterized by a lower percentage of owner-occupied houses.

Cannabis psychosis, gender matters

Purpose

– The purpose of this paper is to draw together key literature and analyses of data on admissions for cannabis psychosis in National Health Service hospitals in England (extracted from Hospital Episode Statistics (HES)) to highlight what is known about gender differences in cannabis psychosis and point towards suggestions for improving gender-sensitive treatment and future research.

Design/methodology/approach

– Analysis of British Crime Survey data and HES data were used in combination with data from previously published epidemiological studies to compare gender differences.

Findings

– Male cannabis users outnumber female users by 2:1, a similar gender ratio is found for those admitted to hospital with a diagnosis of schizophrenia or psychosis. However this ratio increases significantly for those admitted to hospital with a diagnosis of cannabis psychosis, with males outnumbering females by 4:1.

Research limitations/implications

– Consistent patterns in gender ratios for people admitted to hospital with cannabis psychosis over a period of 11 years are reported, it is not clear why this gender difference persists but it warrants further investigation which would be aided by improved gender recording at a systemic level.

Practical implications

– This review brings into focus the marked gender differences in cannabis psychosis. Attending to gender is important for research and treatment with the aim of improving understanding and providing gender-sensitive services.

Originality/value

– This paper adds to the literature on gender differences in cannabis psychosis.

EPA guidance on the early detection of clinical high risk states of psychoses

The aim of this guidance paper of the European Psychiatric Association is to provide evidence-based recommendations on the early detection of a clinical high risk (CHR) for psychosis in patients with mental problems. To this aim, we conducted a meta-analysis of studies reporting on conversion rates to psychosis in non-overlapping samples meeting any at least any one of the main CHR criteria: ultra-high risk (UHR) and/or basic symptoms criteria. Further, effects of potential moderators (different UHR criteria definitions, single UHR criteria and age) on conversion rates were examined. Conversion rates in the identified 42 samples with altogether more than 4000 CHR patients who had mainly been identified by UHR criteria and/or the basic symptom criterion 'cognitive disturbances' (COGDIS) showed considerable heterogeneity. While UHR criteria and COGDIS were related to similar conversion rates until 2-year follow-up, conversion rates of COGDIS were significantly higher thereafter. Differences in onset and frequency requirements of symptomatic UHR criteria or in their different consideration of functional decline, substance use and co-morbidity did not seem to impact on conversion rates. The 'genetic risk and functional decline' UHR criterion was rarely met and only showed an insignificant pooled sample effect. However, age significantly affected UHR conversion rates with lower rates in children and adolescents. Although more research into potential sources of heterogeneity in conversion rates is needed to facilitate improvement of CHR criteria, six evidence-based recommendations for an early detection of psychosis were developed as a basis for the EPA guidance on early intervention in CHR states.

Characteristics of attempted suicide by patients with schizophrenia compared with those with mood disorders: a case-controlled study in northern Japan

Recent reports suggest a lifetime suicide risk for schizophrenia patients of approximately 5%. This figure is significantly higher than the general population suicide risk consequently, detection of those at risk is clinically important. This study was undertaken to define the characteristics of suicide attempts by schizophrenia patients compared with attempts by patients with mood disorders. All patients were diagnosed using the ICD-10 criteria. The study population comprised 65 patients with F2 disorders (schizophrenia, schizotypal and delusional disorders), i.e., “the F2 group”, and 94 patients with F3 disorders (mood disorders), i.e., “the F3 group”, who presented in the clinical setting of consultation-liaison psychiatry. The F2 group had a significantly younger mean age and significantly higher ratios of ‘past/present psychiatric treatment’ and ‘more than 3 months interruption of psychiatric treatment’. In contrast, the ratios of ‘physical disorder comorbidity’, ‘alcohol intake at suicide attempt’ and ‘suicide note left behind’ were significantly higher in the F3 group. The F2 group attempted suicide by significantly more serious methods. Furthermore, ‘hallucination-delusion’ was the most prevalent motive in the F2 group and was the only factor that showed a significant association with the seriousness of the method of suicide attempt (OR = 3.36, 95% CI: 1.05–11.33).