Psychiatric disorders and risky sexual behaviour in young adulthood: crosssectional study in birth cohort

Objective To determine if risky sexual intercourse, sexually transmitted di seases, and sexual intercourse at an early age are associated with psychiat ric disorder. Design Cross sectional study of a birth cohort at age 21 years with assessm ents presented by computer (for sexual behaviour) and by trained interviewe rs (for psychiatric disorder). Setting New Zealand in 1993-4. Participants 992 study members (487 women) from the Dunedin multidisciplina ry health and development study. Complete data were available on both measu res for 930 study members. Main outcome measures Psychiatric disorders (anxiety, depression eating dis order; substance dependence, antisocial disorder, mania, schizophrenia spec trum) and measures of sexual behaviour. Results Young people diagnosed with substance dependence, schizophrenia spe ctrum, and antisocial disorders were more likely to engage in risky sexual intercourse, contract sexually transmitted diseases, and have sexual interc ourse at an early age (before 16 years). Unexpectedly, so were young people with depressive disorders. Young people with mania were more likely to rep ort risky sexual intercourse and have sexually transmitted diseases. The li kelihood of risky behaviour was increased by psychiatric comorbidity. Conclusions There is a clear association between risky sexual behaviour and common psychiatric disorders. Although the temporal relation is uncertain, the results indicate the need to coordinate sexual medicine with mental he alth services in the treatment of young people.