Gender and schizophrenia: association of age at onset with antecedent, clinical and outcome features

Gender, age at onset, and duration of being ill as predictors for the long-term course and outcome of schizophrenia: an international multicenter study

BACKGROUND

The aim of the current study was to explore the effect of gender, age at onset, and duration on the long-term course of schizophrenia.

METHODS

Twenty-nine centers from 25 countries representing all continents participated in the study that included 2358 patients aged 37.21 ± 11.87 years with a DSM-IV or DSM-5 diagnosis of schizophrenia; the Positive and Negative Syndrome Scale as well as relevant clinicodemographic data were gathered. Analysis of variance and analysis of covariance were used, and the methodology corrected for the presence of potentially confounding effects.

RESULTS

There was a 3-year later age at onset for females (P < .001) and lower rates of negative symptoms (P < .01) and higher depression/anxiety measures (P < .05) at some stages. The age at onset manifested a distribution with a single peak for both genders with a tendency of patients with younger onset having slower advancement through illness stages (P = .001). No significant effects were found concerning duration of illness.

DISCUSSION

Our results confirmed a later onset and a possibly more benign course and outcome in females. Age at onset manifested a single peak in both genders, and surprisingly, earlier onset was related to a slower progression of the illness. No effect of duration has been detected. These results are partially in accord with the literature, but they also differ as a consequence of the different starting point of our methodology (a novel staging model), which in our opinion precluded the impact of confounding effects. Future research should focus on the therapeutic policy and implications of these results in more representative samples.

The effect of gender on the long-term course and outcome of schizophrenia in rural Ethiopia: a population-based cohort

BACKGROUND

Although some studies have suggested that women with schizophrenia are more likely to achieve positive outcomes, the evidence-base is fraught with inconsistencies. In this study we compare the long-term course and outcomes for men and women living with schizophrenia in rural Ethiopia.

METHODS

The Butajira course and outcome study for severe mental disorders is a population-based cohort study. Community ascertainment of cases was undertaken between 1998 and 2001, with diagnostic confirmation by clinicians using the Schedules for Clinical Assessment in Neuropsychiatry. Findings from annual outcome assessments were combined with clinical records, patient and caregiver report, and psychiatric assessments at 10-13 years using the Longitudinal Interval Follow-up Evaluation- LIFE chart. For the sub-group of people with schizophrenia (n = 358), we compared course of illness and treatment, co-morbidity, recovery, social outcomes and mortality between men and women. Multivariable analyses were conducted for modelling associations identified in bivariate analyses according to blocks shaped by our a priori conceptual framework of the biological and social pathways through which gender might influence the course and outcome of schizophrenia.

RESULTS

Looking into over 10-13 years of follow-up data, there was no difference in the functioning or recovery in women compared to men (AOR = 1.79, 95% CI = 0.91, 3.57). Women were less likely to report overall life satisfaction (AOR = 0.22, 95% CI = 0.09, 0.53) or good quality of spousal relationships (AOR = 0.09, 95% CI = 0.01-1.04). Men were more likely to have co-morbid substance use and there was a trend towards women being more likely to be prescribed an antidepressant (AOR = 2.38, 95% CI = 0.94, 5.88). There were no gender differences in the course of illness, number of psychotic episodes or adherence to medications.

CONCLUSION

In this rural African setting, we found little evidence to support the global evidence indicating better course and outcome of schizophrenia in women. Our findings are suggestive of a gendered experience of schizophrenia which varies across contexts. Further investigation is needed due to the important implications for the development of new mental health services in low and middle-income country settings.

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.

Admixture analysis of age at onset in schizophrenia: evidence of three subgroups in a first-episode sample

OBJECTIVE

The objective was to assess the presence of different subgroups, via age-at-onset (AAO) analysis, in a schizophrenia population consecutively recruited through an Early Psychosis Service in London, Canada.

METHOD

Admixture analysis was applied in order to identify a model of separate normal distribution of AAO characterized by different means, variances and population proportions to allow for evaluation of different subgroups in a sample of 187 unrelated patients with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis of schizophrenia.

RESULTS

The best-fitting model suggested three subgroups with means and standard deviations of 16.8 ± 1.9, 22.3 ± 2.1 and 32.7 ± 5.9 years comprising 41%, 30% and 29% of the schizophrenia sample, respectively. These three subgroups were categorized as early, intermediate and late onset with cutoffs determined by admixture analysis to be 19 and 26 years of age, respectively. In our investigation, the definition of early-onset schizophrenia is the main outcome. We considered the clinical variables mainly related to the heritability and neurobiology of schizophrenia. Single status was strongly associated with early onset (P<.001). The male gender (P=.023), as well as a history of drug abuse (P=.004), was significantly associated with early onset. Interestingly, lower academic achievement was also associated with early-onset schizophrenia (P<.001).

CONCLUSION

Overall, our study showed that a typical early-onset schizophrenia patient is more likely to be a single male, with a history of drug abuse and birth complications, and lower academic achievement as compared to the late-onset subgroup.

Gender difference in age at onset of schizophrenia: a meta-analysis

BACKGROUND

Most studies reporting the gender difference in age at onset of schizophrenia show an earlier onset in males, but vary considerably in their estimates of the difference. This may be due to variations in study design, setting and diagnostic criteria. In particular, several studies conducted in developing countries have found no difference or a reversed effect whereby females have an earlier onset. The aim of the study was to investigate gender differences in age of onset, and the impact of study design and setting on estimates thereof.

METHOD

Study methods were a systematic literature search, meta-analysis and meta-regression.

RESULTS

A total of 46 studies with 29,218 males and 19,402 females fulfilled the inclusion criteria and were entered into a meta-analysis. A random-effects model gave a pooled estimate of the gender difference of 1.07 years (95% confidence interval 0.21-1.93) for age at first admission of schizophrenia, with males having earlier onset. The gender difference in age at onset was not significantly different between developed and developing countries. Studies using diagnostic and statistical manual of mental disorders (DSM) criteria showed a significantly greater gender difference in age at onset than studies using International Classification Of Diseases (ICD) criteria, the latter showing no difference.

CONCLUSIONS

The gender difference in age of onset in schizophrenia is smaller than previously thought, and appears absent in studies using ICD. There is no evidence that the gender difference differs between developed and developing countries.

A Review of Brain-derived Neurotrophic Factor as a Candidate Biomarker in Schizophrenia

Brain-derived neurotrophic factor (BDNF), a neurotrophin known to be responsible for development, regeneration, survival and maintenance of neurons has been implicated in the pathophysiology of schizophrenia. This review seeks to complement previous reviews on biological roles of BDNF and summarizes evidence on the involvement of BDNF in the pathophysiology of schizophrenia with an emphasis on clinical relevance. The expressions of BDNF were altered in patients with schizophrenia and were found to be correlated with psychotic symptomatology. Antipsychotics appeared to have differential effects on expression of BDNF but did not restore BDNF expression of patients with schizophrenia to normal levels. In addition, evidence suggests that BDNF is involved in the major neurotransmitter systems and is associated with disruptions in brain structure, neurodevelopmental process, cognitive function, metabolic and immune systems commonly associated with schizophrenia. Besides that, BDNF has been demonstrated to be tightly regulated with estrogen which has also been previously implicated in schizophrenia. Evidence gathered in this review confirms the relevance of BDNF in the pathophysiology of schizophrenia and the potential utility of BDNF as a suitable biomarker for diagnostic and prognostic purposes for disease outcome and other co-morbidities. However, further investigations are warranted to examine the specificity of BDNF in schizophrenia compared to other neurodegenerative disorders and other neuropsychiatric illness. Longitudinal prospective studies will also be of added advantage for evaluation of prognostic utility of BDNF in schizophrenia.

The influence of gender on clinical and social characteristics of patients at psychosis onset: A report from the Psychosis Incident Cohort Outcome Study (PICOS)

BACKGROUND. This paper examined the hypothesis that males with first-episode psychosis (FEP) experience lower pre-morbid adjustment, greater social disability and more self-perceived needs at illness onset than females(by controlling for duration of untreated psychosis, diagnosis, age and symptoms at onset). Results disconfirming this hypothesis were thought to suggest the potentially mediating role of social context in determining the impact of symptoms and disability on the everyday lives of male patients in the early phase of psychosis. METHOD. A large epidemiologically representative cohort of FEP patients (n=517) was assessed within the Psychosis Incident Cohort Outcome Study (PICOS) framework – a multi-site research project examining incident cases of psychosis in Italy's Veneto region. RESULTS. Despite poorer pre-morbid functioning and higher social disability at illness onset, males reported fewer unmet needs in the functioning domain than females did. An analysis of help provided by informal care givers showed that males received more help from their families than females did. This finding led us to disconfirm the second part of the hypothesis and suggest that the impact of poorer social performance and unmet needs on everyday life observed in male patients might be hampered by higher tolerance and more support within the family context.CONCLUSIONS. These findings shed new light on rarely investigated sociocultural and contextual factors that may account for the observed discrepancy between social disability and needs for care in FEP patients. They also point to a need for further research on gender differences, with the ultimate aim of delivering gender-sensitive effective mental health care.

Similarities in early course among men and women with a first episode of schizophrenia and schizophreniform disorder

The aims of this study were to analyze the presence of gender differences in the phenotypic expression of schizophrenia at the onset of illness and to explore whether these differences determine clinical and functional outcome 2 years after the initiation of treatment. Data from 231 first-episode-psychosis non-substance-dependent patients (156 men and 75 women) participating in a large-scale naturalistic open-label trial with risperidone were recorded at inclusion and months 1, 6, 12, and 24. Men presented a significant earlier age of onset (24.89 years vs. 29.01 years in women), poorer premorbid functioning, and a higher presence of prodromal and baseline negative symptoms. Women were more frequently married or lived with their partner and children and more frequently presented acute stress during the year previous to onset than men. No other significant clinical or functional differences were detected at baseline. The mean dose of antipsychotic treatment was similar for both genders during the study, and no significant differences in UKU scores were found. The number of hospitalizations was similar between groups, and adherence was more frequent among women. At the 2-year follow-up, both groups obtained significant improvements in outcome measures: PANSS, CGI severity, and GAF scores. Significant gender * time interactions were detected for negative and general PANSS subscales, with the improvement being more pronounced for men. However, no differences were detected for the mean scores obtained during the study in any outcome measure, and the final profile was similar for men and women. Our results suggest that although the initial presentation of schizophrenia can differ according to gender, these differences are not sufficient enough to determine differentiated outcome 2 years after the initiation of treatment in non-substance-dependent patients. The influence of gender on the early course of schizophrenia does not seem to be clinically or functionally decisive in this population.

Gender differences in Singaporean Chinese patients with schizophrenia

The purpose of this study was to compare gender differences in age of onset of illness, clinical features and prescription patterns in Chinese schizophrenia patients in Singapore. A cross-sectional study was conducted which recruited 903 subjects diagnosed with schizophrenia from the Institute of Mental Health between 2005 and 2008. Information on age of onset of schizophrenia, body mass index (BMI), psychiatric family history and current medication was collected via a standardised collection form. Symptom severity was assessed with Positive and Negative Syndrome Scale (PANSS). Differences in age of onset of schizophrenia illness, clinical features and prescription patterns were compared between gender groups. Among sporadic schizophrenia cases, female subjects demonstrated a bimodal distribution in age of onset of illness, and had a significantly later age of illness onset compared with male subjects. For subjects with family history of psychiatric disorder, no significant gender differences were found in age of onset of illness. Female subjects had significantly higher BMI, higher proportion of diabetes mellitus, lower negative symptom scores and were prescribed more atypical antipsychotics and antidepressants compared with male subjects. Male subjects after age 50 were prescribed a lower antipsychotic dose, but this difference was not observed in female subjects. In conclusion, we found differences in age of onset of schizophrenia, severity of negative symptoms and prescription patterns between the male and female gender groups in Chinese schizophrenia patients in Singapore. These differences were consistent with findings from Caucasian population, and could possibly be explained by influences of oestrogen.

Gender differences in patients presenting with first-episode psychosis in Hong Kong: a three-year follow up study

OBJECTIVE

The aim of the current study was to investigate gender differences with respect to pre-treatment characteristics, clinical presentation, service utilization and functional outcome in patients presenting with first-episode psychosis.

METHODS

A total of 700 participants (men, n = 360; women, n = 340) aged 15 to 25 years consecutively enrolled in a territory-wide first-episode psychosis treatment programme in Hong Kong from July 2001 to August 2003 were studied. Baseline and three-year follow up variables were collected via systematic medical file review.

RESULTS

At service entry, men had significantly lower educational attainment (p < 0.01), longer median duration of untreated psychosis (p < 0.001), fewer past suicidal attempts (p < 0.01), more severe negative symptoms (p < 0.05) and fewer affective symptoms (p < 0.01) than women. There was no significant gender difference in age of onset. In three-year follow up, men had more prominent negative symptoms (p < 0.001), fewer affective symptoms (p < 0.01), more violent behaviour and forensic records (p < 0.01), and higher rate of substance abuse (p < 0.01). Women achieved higher levels of functioning than men (Social Occupational Functioning Assessment Scale (SOFAS), p < 0.001) and a significantly higher proportion of women than men engaged in full-time employment or study for at least 12 consecutive months (p < 0.001) in the initial three years after psychiatric treatment.

CONCLUSION

Notable gender differences in clinical profiles, illness trajectory and functional outcome were demonstrated in Chinese young people suffering from first-episode psychosis. Differential needs between men and women and hence gender-specific therapeutic strategies should be considered in early intervention service.

Gender differences in premorbid, entry, treatment, and outcome characteristics in a treated epidemiological sample of 661 patients with first episode psychosis

OBJECTIVES

Gender differences in psychotic disorder have been observed in terms of illness onset and course; however, past research has been limited by inconsistencies between studies and the lack of epidemiological representative of samples assessed. Thus, the aim of this study was to elucidate gender differences in a treated epidemiological sample of patients with first episode psychosis (FEP).

METHODS

A medical file audit was used to collect data on premorbid, entry, treatment and 18-month outcome characteristics of 661 FEP consecutive patients treated at the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne, Australia.

RESULTS

Prior to onset of psychosis, females were more likely to have a history of suicide attempts (p=.011) and depression (p=.001). At service entry, females were more likely to have depressive symptoms (p=.007). Conversely, males had marked substance use problems that were evident prior to admission (p<.001) and persisted through treatment (p<.001). At service entry, males also experienced more severe psychopathology (p<.001) and lower levels of functioning (GAF, p=.008; unemployment/not studying p=.004; living with family, p=.003). Treatment non-compliance (p<.001) and frequent hospitalisations (p=.047) were also common for males with FEP. At service discharge males had significantly lower levels of functioning (GAF, p=.008; unemployment/not studying p=.040; living with family, p=.001) compared to females with FEP.

CONCLUSIONS

Gender differences are evident in illness course of patients with FEP, particularly with respect to past history of psychopathology and functioning at presentation and at service discharge. Strategies to deal with these gender differences need to be considered in early intervention programs.

Relationship between gross domestic product and duration of untreated psychosis in low- and middle-income countries

BACKGROUND

The duration of untreated psychosis (DUP), the period between the first onset of psychotic symptoms and treatment, has an important influence on the outcome of schizophrenia.

AIMS

To compare the published studies of DUP in low- and middle-income (LAMI) countries with the DUP of high-income countries, and examine a possible association between DUP and per capita income.

METHOD

We used six search strategies to locate studies of the DUP from LAMI countries published between January 1975 and January 2008. We then examined the relationship between DUP and measures of economic activity, which was assessed using the LAMI classification of countries and gross domestic product (GDP) purchasing power parity.

RESULTS

The average mean DUP in studies from LAMI countries was 125.0 weeks compared with 63.4 weeks in studies from high-income countries (P=0.012). Within the studies from LAMI countries, mean DUP fell by 6 weeks for every $1000 of GDP purchasing power parity.

CONCLUSIONS

There appears to be an inverse relationship between income and DUP in LAMI countries. The cost of treatment is an impediment to care and subsidised antipsychotic medication would improve the access to treatment and the outcome of psychotic illness in LAMI countries.

Premorbid adjustment, symptom development and quality of life in first episode psychosis: a systematic review and critical reappraisal

OBJECTIVE

To systematically review the relationship of premorbid adjustment to symptomatology in first episode psychosis (FEP), taking into account the influence of duration of untreated psychosis (DUP).

METHOD

Electronic databases were searched to identify relevant studies.

RESULTS

A variety of approaches to the reporting of premorbid adjustment were identified. There was no significant association between premorbid adjustment and DUP, supporting the proposition that they are independent constructs. The effect of premorbid adjustment upon positive symptomatology was negligible. Premorbid adjustment had a modest effect upon negative symptoms and quality of life, increasing over duration of follow-up.

CONCLUSION

Premorbid adjustment remains a valid construct in the study of FEP. Both premorbid adjustment and DUP confer independent effects on aspects of symptomatology in FEP. Results for premorbid adjustment are similar to previous findings in more chronic samples. The potential for conceptualizing premorbid functioning by developmental, academic/social and typological approaches is currently underexploited.