1. During the period January 1930 to January 1940, 68 cases of involutional psychoses were admitted to the Norwich State Hospital, representing 0.8% of the total admissions. 17 died within 6 months, leaving 51 cases for the present study.2. Twenty-three (45%) had left the hospital as recovered or improved at the expiration of this period. Twenty-eight (55%) were unimproved or worse.3. The prognostic significance of sex, marital status, time of onset and elapsed period before hospitalization, positive family history, relationship to menopause, effect of treatment, and prepsychotic personality was investigated.4. Depressive features, such as agitation, sadness, self-accusatory and self-depreciative ideas, somatic delusions, suicidal threats and attempts, predominated in 78% of those that got well.5. Schizophrenic symptoms, such as auditory and visual hallucinations, ideas of persecution, systematized delusions and catatonic behavior, were associated with an unfavorable outcome.6. An analysis of the development and eventual outcome of the case material suggests the conclusion that involutional psychosis might more properly be diagnosed either manic-depressive psychosis or schizophrenia which has occurred late in life.Abstract Teaser