Association between childhood psychiatric disorders and psychotic experiences in adolescence: A population-based longitudinal study

BACKGROUND Adolescent psychotic experiences (PEs) are common, and are associated with both psychotic and non-psychotic illnesses. In order to examine psychopathological and cognitive antecedents of adolescent PEs, we have conducted a longitudinal study of common childhood psychiatric disorders and subsequent adolescent PEs in the population-based prospective ALSPAC birth cohort. METHOD Depression, anxiety, attention deficit hyperactivity disorder, oppositional defiant or conduct disorder, and pervasive developmental disorder were diagnosed according to DSM-IV criteria in 8253 participants at age 8years. IQ was assessed by WISC-III also at 8years. PEs, depressive and anxiety symptoms were assessed at 13years. Logistic regression calculated odds ratio (OR) for PEs at 13years associated with psychiatric disorders at 8years. Linear regression calculated mean difference in IQ between groups with and without psychiatric disorder. Mediating effects of IQ, mood and anxiety symptoms on the psychiatric disorder-PEs relationship were examined. RESULTS In total, 599 children were assessed to have a DSM-IV psychiatric disorder at 8years (7.2%). These children compared with those without any psychiatric disorder performed worse on all measures of IQ; adjusted mean difference in total IQ -6.17 (95% CI, -7.86, -4.48). Childhood psychiatric disorders were associated with PEs subsequently in adolescence; adjusted OR 1.96 (95% CI, 1.47-2.68). The association between psychiatric disorder and subsequent PEs was partly mediated by, independently, IQ deficit at 8years and depressive and anxiety symptoms at 13years. CONCLUSIONS The findings indicate that adolescent PEs are associated with general cognitive ability and past and present psychopathological factors.