The Fast Track (FT) intervention was a multimodal preventive intervention addressing antisocial development across 10 years of childhood and early adolescence. The intervention included parent management training, child social-cognitive skills training, peer coaching and mentoring, academic skills tutoring, and a classroom social-emotional learning program. While not specifically designed to target psychosis symptoms (e.g., social withdrawal, thought abnormalities), the present study aimed to examine whether the FT intervention prevented psychosis symptoms through childhood and adolescence and into adulthood. Participants included the FT intervention and high-risk control samples (N = 891; 69% male; M age = 6.58 years, SD = .48). Psychosis symptoms were assessed using the "thought problems" subscale of the parent-report Child Behavior Checklist during grades 1, 2, 4, 5, and 7, and the self-report Adult Behavior Checklist at age 25 years, in line with prior research using this measure. Growth models included the FT condition and covariates (i.e., initial risk screen score, cohort, socioeconomic status, rural/urban status, race, and sex) as predictors; and child, adolescent, and adult psychosis symptoms as outcomes. Intervention status was not significantly associated with the slope of psychosis symptoms; however, after controlling for concurrent cannabis use, intervention participants reported lower levels of psychosis symptoms over time. Findings suggest that interventions targeting antisocial behavior may prevent psychosis symptoms in the long term.
Keywords: Cannabis; Intervention; Prevention; Psychosis.