Influence of season and latitude in a community sample of subjects with bipolar disorder.

<bold>Objective: </bold>To report on the prevalence of seasonal bipolar disorder (BD) and the impact of latitude in a community sample in the province of Ontario.<bold>Method: </bold>This study used the telephone-administered Depression and Seasonality Interview. Exact latitude was determined for each participant.<bold>Results: </bold>Overall, 14 of 62 (22.6%) subjects with BD had the seasonal subtype of BD. Latitude did not appear to influence the proportion of subjects with the seasonal subtype.<bold>Conclusions: </bold>We identified a seasonal pattern of illness in a proportion of subjects with BD. [ABSTRACT FROM AUTHOR]