Childhood trauma and children's emerging psychotic symptoms: A genetically sensitive longitudinal cohort study.

OBJECTIVE Using longitudinal and prospective measures of trauma during childhood, the authors assessed the risk of developing psychotic symptoms associated with maltreatment, bullying, and accidents in a nationally representative U.K. cohort of young twins. METHOD Data were from the Environmental Risk Longitudinal Twin Study, which follows 2,232 twin children and their families. Mothers were interviewed during home visits when children were ages 5, 7, 10, and 12 on whether the children had experienced maltreatment by an adult, bullying by peers, or involvement in an accident. At age 12, children were asked about bullying experiences and psychotic symptoms. Children's reports of psychotic symptoms were verified by clinicians. RESULTS Children who experienced mal-treatment by an adult (relative risk=3.16, 95% CI=1.92-5.19) or bullying by peers (relative risk=2.47, 95% CI=1.74-3.52) were more likely to report psychotic symptoms at age 12 than were children who did not experience such traumatic events. The higher risk for psychotic symptoms was observed whether these events occurred early in life or later in childhood. The risk associated with childhood trauma remained significant in analyses controlling for children's gender, socioeconomic deprivation, and IQ; for children's early symptoms of internalizing or externalizing problems; and for children's genetic liability to developing psychosis. In contrast, the risk associated with accidents was small (relative risk=1.47, 95% CI=1.02-2.13) and inconsistent across ages. CONCLUSIONS Trauma characterized by intention to harm is associated with children's reports of psychotic symptoms. Clinicians working with children who report early symptoms of psychosis should inquire about traumatic events such as maltreatment and bullying.