Neurophysiological evidence for different types of depression.

A brief, selective review of a broad range of evidence bearing upon biological distinctions between neurotic and psychotic forms of depression is presented. It includes a somewhat detailed presentation of clinical neurophysiological findings obtained in the author's laboratory over three decades of research. The available evidence is taken to support the discontinuity position of the continuity-discontinuity controversy about neurotic vs psychotic depression. It is concluded that more than one process underlies clinical depression, and that there may be several kinds of depressive disorders.