Review: Efficacy of preventative interventions for children and adolescents at clinical high risk of psychosis - a systematic review and meta-analysis of intervention studies

BackgroundDespite evidence suggesting that age moderates the response to preventative treatment for those at clinical high risk of psychosis (CHR-P), no meta-analysis has assessed the effectiveness of preventative interventions for CHR-P children and adolescents. Our aim was to synthesise evidence assessing preventative interventions on a wide range of mental health outcomes for CHR-P children and adolescents.MethodA systematic search was conducted on Ovid MEDLINE, Pubmed, APA PsycInfo and Web of Science until June 2024 (PROSPERO: CRD42023406696). Intervention studies that had a mean participant age of under 18 years old that reported on mental health outcomes for CHR-P participants were selected. A meta-analysis was conducted for independent studies reporting the effectiveness of interventions on different outcomes (transition to psychosis, attenuated positive, negative and total prodromal psychotic symptoms, depressive symptoms and global functioning) compared to control conditions of no intervention or placebo. Evidence from other studies was also reported narratively.ResultsTwenty-four studies and 1319 CHR-P children and adolescents were included. Compared to no intervention or placebo, preventative interventions were effective for positive symptoms (SMD = 0.379, p = .022, 95% CI 0.055, 0.703), negative symptoms (SMD = 0.583, p = .004, 95% CI 0.187, 0.980), total symptoms (SMD = 0.677, p = .002, 95% CI 0.249, 1.105) and functioning (SMD = 0.944, p = .038, 95% CI 0.052, 1.836) but not reducing transition to psychosis or depressive symptoms.ConclusionsThere are disparities in the effectiveness of preventative interventions for different outcomes, with transition to psychosis not being the only relevant outcome. Differences in the efficacy of preventative interventions emerged between CHR-P children and adolescents versus adults.