Predominant polarity in bipolar I and Ii disorders: A five-year follow-up study

•A five-year prospective study of predominant polarity in 191 bipolar patients.•Predominant polarity was manic in 16%, intermediate in 48% and depressive in 36%.•The manic polarity group had best outcome with regard to time ill.•The depressive polarity group had highest incidence of suicide attempts.•The stability of classification of predominant polarity over time was only moderate.