“…Studies directly comparing the premorbid functioning of persons with schizophrenia and those with affective psychosis have shown greater impairments in intellectual and social functioning in the schizophrenia group (22,31,32). Studies comparing social and intellectual functioning during childhood in future affective psychosis patients, compared with healthy comparison subjects, have reported mixed results: some found no significant premorbid social or intellectual abnormalities in future affective psychosis patients (3,14,23,30), and others have found such abnormalities (20,21,33).…”