Of 840 patients diagnosed as having bipolar and unipolar affective disorder, schizophrenia, or a schizophreniform psychosis, follow-up information was available for 94%. Followed long enough (ten years), nearly all affective disorder patients appeared to recover. Only 8% of schizophrenic patients ever recovered, compared to 22% of those with schizophreniform psychoses; most recoveries were seen to occur within the first two or three years posthospitalization. No patient with affective disorder followed ten years or more remained continuously hospitalized, whereas 20% of schizophrenic patients and 5% of patients with schizophreniform psychosis had never been released from the hospital; these percentages remained constant after five years. Strict criteria can predict those likely to recover and those to require chronic care; cases which contradict the prediction do so within the first few years after index admission.
Morrison J, Winokur G, Crowe R, Clancy J. The Iowa 500The First Follow-Up. Arch Gen Psychiatry. 1973;29(5):678-682. doi:10.1001/archpsyc.1973.04200050083014