Psychotic-like experiences in pre-adolescence: what precedes the antecedent symptoms of severe mental illness?

Objective: Adolescent psychotic-like experiences predict the onset of psychosis, but also predict subsequent non-psychotic disorders. Therefore, it is crucial to better understand the aetiology of psychotic-like experiences. This study examined whether (a) child emotional and behavioural problems at 3 and 6 years, or (b) childhood adversities were associated with psychotic-like experiences at age 10 years. Method: This prospective study was embedded in the Generation R Study; 3984 children (mean age 10 years) completed a psychotic-like experiences questionnaire. Mothers reported problems of their child at ages 3, 6 and 10 years. Additionally, mothers were interviewed about their child's adversities. Results: Psychotic-like experiences were endorsed by similar to 20% of children and predicted by both emotional and behavioural problems at 3 years (e.g. emotional-reactive problems: ORadjusted = 1.10, 95% CI: 1.06-1.15, aggressive behaviour: ORadjusted = 1.03, 95% CI: 1.02-1.05) and 6 years (e.g. anxious/depressed problems: ORadjusted = 1.11, 95% CI: 1.06-1.15, aggressive behaviour: ORadjusted = 1.04, 95% CI: 1.04-1.05). Childhood adversities were associated with psychotic-like experiences (>2 adversities: ORadjusted = 2.24, 95% CI: 1.72-2.92), which remained significant after adjustment for comorbid psychiatric problems. Conclusion: This study demonstrated associations between early adversities, childhood emotional and behavioural problems and pre-adolescent psychotic-like experiences, which will improve the understanding of children at increased risk of severe mental illness.