Clinical high risk for psychosis in children and adolescents: A meta-analysis of transition prevalences

The strategic value of early, preventive intervention in psychosis has been a catalytic stepping stone to promoting early intervention in Mental Health. Central to such momentum is the construct of clinical high risk states for psychosis (CHR). While CHR emerge in developmental years, the meta-analytical risk of psychosis among children and adolescents (age 9–18 years) at CHR is still unknown. We conducted a meta-analysis according to PRISMA guidelines including all studies that assessed CHR in children and adolescents (age ≤ 18 years) with validated instruments and provided follow-data on transition to psychosis up to December 31, 2018. We identified 11 eligible studies. Mean age was 15.8 ± 0.8 years, range: 13.8 to 16.8. Transition to psychosis occurred in 93 CHR subjects out of 533 that were enrolled at inception, over a follow-up period ranging from 6 to 72 months. Conversion prevalence was 17.5% (95% CI: 9.9% to 26.5%) in the random-effects model (Q = 30.9; p < .001; I2 = 68%), and slightly lower (16.0; 12.9% to 19.5%) in the fixed-effect model. Gender ratio, the criteria used to diagnose the CHR status, and quality of studies had an impact on the estimates of conversion prevalence in the intention-to-treat model without the outlier. Studies of fair quality produced lower estimates of conversion prevalence (11%; 95% CI: 2% to 24%) than those produced by studies of good quality (19%; 95% CI: 11% to 28%). These findings suggest that CHR in adolescence presents commensurable transition prevalences to those found in adult samples, confirming the relevance of CHR criteria for timely risk inception in developmental years. Outcomes other than transition to psychosis (e.g. remission, persistent CHR, socio-functional status or treatment responses) were not systematically reported thereby preventing further, more sophisticated, prognostic stratifications.