A review of the natural course of bipolar disorders (manic–depressive psychosis) in the pre-drug era: Review of studies prior to 1950

A review of the most important original studies describing the natural course of bipolar isorder (manic–depressive psychosis) published in the pre-drug era – before 1950 – is conducted. Discrepancies among studies are detected, most of which are likely explained by methodological differences.However, some conclusions from these old studies remain perfectly valid nowadays: mania is a chronic brain disorder, inherited in most cases, decompensation being more frequent between March and August. It is more common in males, and in some cases, is secondary to other somatic problems. Mixed states are more frequent in the elderly.The review of this type of historical studies is aimed at underscoring the importance that should be attached to the careful study of psychopathology and its recording, both in clinical practice and in psychiatry research.