Seasonal variation in hospital admission for bipolar disorder, depression and schizophrenia in Tasmania

Objective: Seasonal variation has been reported for both affective disorders and schizophrenia. The current study examines seasonal variation in admissions in schizophrenia, depression and bipolar disorder in Tasmania, the southernmost state of Australia. Method: All admissions with a diagnosis of schizophrenia, bipolar disorder and depression in Tasmania between 1983 and 1989 were examined for evidence of seasonal variation in admission patterns. Results: Using the modified Kolmogorov-Smirnov statistic defined by Freedman no significant seasonal variation was found in admissions with diagnoses of mania, depression or schizophrenia. There was a significant seasonal variation in admissions with schizoaffective disorder (winter peak). Conclusion: There is no significant seasonal variation in admissions with schizophrenia, depression or bipolar disorder in Tasmania, This may be due to a combination of geographical location and the stringent test of seasonal variation used in the current study.