Early adverse experiences in schizophrenia and unipolar depression

To study the prevalence of early adversities in schizophrenia and unipolar depression, 2 groups of consecutive adult-onset inpatients with DSM-IV diagnoses of schizophrenia (n = 173) and unipolar depression (n = 305) were compared with an unscreened control group of volunteers from the general population (n = 310), with respect to their association with 4 types of childhood abuse and with early parental adversities (discord, separation, death, psychiatric caseness). Compared with general population, most types of early adversities (except sexual abuse and parental death) were significantly associated with both clinical groups. Compared with depression, all early adversities with the same 2 exceptions were significantly associated with schizophrenia; both frequency of abuse and number of types of abuse increased the risk of schizophrenia in a dose-response pattern, suggesting causality. These findings stress the role of social developmental factors in the etiology of schizophrenia.