Monozygotic twins discordant for schizophrenia

Summary The study of MZ twins discordant for schizophrenia can shed light on important experiential factors in the development of at least some cases of schizophrenia. The gradual development of paranoid schizophrenia was described in an MZ male twin who later recovered completely from his illness. His life pattern was compared with that of his non-psychotic co-twin, and his early characteristics and development were contrasted with features of schizophrenic twins in discordant pairs in a recently reported summary of such cases. It is suggested that late onset paranoid schizophrenia is different in many ways from other subtypes of schizophrenia beginning in adolescence.From Queen's University, Kingston, Ontario, Canada, this paper was submitted to theQuarterly on June 16, 1969.