The Chicago Follow-up Study is a prospective, multidimensional investigation of the longitudinal course and clinical correlates of schizophrenia and other major psychiatric disorders. A total of 139 participants were recruited from their first hospitalisation, and followed up at approximately 2, 4.5, 7.5, 10, 15, and 20 years. At recruitment, 61 patients had schizophrenia, 9 were schizoaffective patients, and 69 initially psychotic mood disordered patients were used as a control sample. All but 3 patients were aged between 17 and 32 years.