Family History Studies: VII. Manic Depressive Disease Versus Depressive Disease

Abstract

During the past twenty years, the unity of manic-depressive disease as defined by Kraepelin (1913) has been questioned by investigators who have presented clinical and genetic evidence that the disease is heterogeneous and contains at least two discrete groups (Leonhard, 1957; Perris, 1966). In one of these groups mania occurs and patients exhibit both manic and depressive phases during the course of their illness. This group has been designated bipolar by most investigators (Leonhard, 1957; Perris, 1966). In the other group there are only episodes of depression, and this has been designated the unipolar group by some (Perris, 1966) and corresponds largely to the ‘monopolar’ group of Leonhard (1957). In this paper we shall use the term unipolar throughout to designate an affective illness in which only depression occurs.