Schizophrenia and other psychotic disorders in a cohort of sexually abused children.

CONTEXT: The evidence for an association between child sexual abuse and subsequently developing psychotic disorders, including the schizophrenias, remains inconclusive.

OBJECTIVE: To explore whether child sexual abuse is a risk factor for later psychotic disorders.

DESIGN: Case-control study.

SETTING: Sample drawn from all notified cases of child sexual abuse over a 30-year period in Victoria, Australia.

PARTICIPANTS: A cohort of 2759 individuals ascertained as having been sexually abused when younger than 16 years had their subsequent contacts with mental health services established by data linkage. They were compared with a community-based control group matched on sex and age groupings whose rates of disorder were established using identical methods.

MAIN OUTCOME MEASURES: Rates of psychotic and schizophrenic illnesses.

RESULTS: Rates were significantly higher among child sexual abuse subjects compared with controls for psychosis in general (2.8% vs 1.4%; odds ratio, 2.1; 95% confidence interval, 1.4-3.1; P < .001) and schizophrenic disorders in particular (1.9% vs 0.7%; odds ratio, 2.6; 95% confidence interval, 1.6-4.4; P < .001). Those exposed to penetrative abuse had even higher rates of psychosis (3.4%) and schizophrenia (2.4%). Abuse without penetration was not associated with significant increases in psychosis or schizophrenia. The risks were highest for those whose abuse involved penetration, occurred after age 12 years, and involved more than 1 perpetrator, the combination producing rates of 8.6% for schizophrenia and 17.2% for psychosis.

CONCLUSIONS: Child sexual abuse involving penetration is a risk factor for developing psychotic and schizophrenic syndromes. The risk is greater for adolescents subjected to penetration. Irrespective of whether this statistical association reflects any causal link, it does identify an at-risk population in need of ongoing support and treatment.