Risk factors for the late-onset psychoses: a systematic review of cohort studies.

BACKGROUND: Psychoses with onset in late adulthood are challenging. Identifying those older patients at risk would be clinically important and would have research implications. METHODS: A computer search was performed to identify all cohort studies of risk factor(s) for psychotic symptoms or disorders with onset at 40 years or older. Experts were contacted and bibliographies were screened for additional references. Validity of located studies was assessed according to evidence-based medicine criteria for risk factors studies. Data were extracted and tabulated for qualitative and quantitative analyses. RESULTS: Twelve articles were retrieved, corresponding to 11 studies of 32 potential risk factors. In the qualitative analysis, only the history of psychotic symptoms, cognitive problems, poor health status, visual impairment, and negative life events appeared to be significant risk factors of late-onset psychosis. Older age, female gender, and hearing impairment were not associated with psychosis in older patients. Quantitative analysis was feasible with only one item, female gender, and confirmed the lack of associated risk with late-onset psychosis. CONCLUSIONS: Despite the methodological limitations of the studies included in this review, there is some evidence from cohort studies that history of psychotic symptoms, cognitive problems, poor physical health, visual impairment, and negative life events are risk factors for late-onset psychosis. More long-term follow-up studies are needed to confirm these findings.