Since the discovery of peptides in hypophysis and brain, several classes of these peptides have been tested on their putative antidepressive properties. The clinical research was stimulated both by the symptomatology of depressive disorders and the demonstrated neuro-endocrine disturbances which frequently occur in such syndromes, and the data obtained in investigations of CSF, blood and post-mortem material. In this concise review, attention will be focussed only upon the results from clinical studies with releasing and release-inhibiting factors and hypophyseal hormones respectively.