Bipolar affective disorder

Abstract

Abstract Bipolar affective disorder is the term currently used for what was originally called ‘manic–depressive psychosis’. Manic–depressive psychosis was one of the major mental illnesses that Kraepelin distinguished in his original studies (Kraepelin 1919) and it affects just under 0.7% of the adult population (Weissman et al. 1996). He distinguished it from schizophrenia (then called ‘dementia praecox’) not so much on the grounds of the symptoms as on the course of the illness. Dementia praecox was characterized by a gradual decline in functioning punctuated by episodes of severe disturbance, but manic–depressive patients often showed full recovery between episodes, although the disturbed periods could be equally severe. French psychiatrists called it ‘folie circulaire’ (Falret 1854).