Predominant polarity of bipolar patients in Israel.

Studies in European and American populations have suggested that the course of bipolar illness is most often characterised by a predominance of depressions over manias. The current chart review study suggests that among manic-depressive patients in Southern Israel, a predominately manic course of illness is more common. Unlike some previous studies, no sex differences were noted in type of illness course. Possible explanations for the main finding, including climate-related factors, are discussed.