The Iowa 500: field work in a 35-year follow-up of depression, mania, and schizophrenia.

This paper reports a follow-up and family study being carried out at the University of Iowa College of Medicine on primary affective disorders and schizophrenia in patients hospitalized thirty-five years ago. The purpose of this project is to obtain objective data to shed light on our understanding of these two major functional psychoses -- their diagnostic validity, clinical features, course and outcome, heterogeneity, life histories, related illnesses and characteristics of familial association. This research started with 525 patients selected from inpatients consecutively admitted to the Iowa Psychopathic Hospital between 1934 and 1944, and with a stratified random sample of 160 surgical patients admitted to the University General Hospital during the same period. A specially designed structured interview form -- the Iowa Structured Psychiatric Interview (ISPI) -- is used to follow up all living index patients, and as many of their living first-degree relatives as possible. At this time, over one-third of the estimated total study population of three thousand patients and relatives have been personally interviewed, and the preliminary findings are reported here.