What mediates the longitudinal relationship between psychotic experiences and psychopathology?

Psychotic experiences (PEs) are common in early adolescence and are associated with nonpsychotic psychopathology. However, not all adolescents with PEs have subsequent psychopathology, and vice versa. To date, factors mediating the relationship between PEs and psychopathology have been understudied. The aims of this study were to investigate the bidirectional relationship between PEs and psychopathology in adolescence and to investigate potentially malleable mediators of these relationships. Data from 2 waves (age 13 and 17 years) of Cohort '98 of the Growing Up in Ireland study were examined (n = 6,206). Using KHB pathway decomposition, we investigated the following as potential mediators of the relationship between psychopathology and PEs: parent-child relationship (conflict and positive), self-concept, and child-peer relationship (alienation and trust). Supplementary counterfactual mediation and sensitivity analyses were conducted. Early adolescents with psychopathology had twofold increased odds of late adolescent PEs (internalizing problems: odds ratio [OR] = 2.03, 95% confidence interval [CI; 1.56, 2.62]; externalizing problems: OR = 1.99, CI [1.51, 2.60]). Parent-child conflict explained between 23% and 34% of the associations between internalizing and externalizing problems and subsequent PEs. Early adolescents with PEs had increased odds of late adolescent psychopathology (internalizing problems: OR = 2.01, CI [1.61, 2.50]; externalizing problems: OR = 1.70, CI [1.25, 2.31]). Self-concept alone accounted for 52% of the relationship between PEs and subsequent internalizing problems. There is a bidirectional heterotypic relationship between psychopathology and PEs. Parent-child conflict and self-concept are important characteristics that mediate a proportion of the relationship between PEs and psychopathology. Interventions targeting parent-child conflict in the context of psychopathology and self-concept in the context of PEs may assist in reducing the incidence of poorer outcomes. Psychotic experiences are common in adolescence and are frequently associated with other mental health problems. However, not all young people with psychotic experiences have mental health problems, and most with mental health problems do not have psychotic experiences. We found that psychotic experiences are bidirectionally associated with mental health problems. The relationship between psychotic experiences and subsequent mental health problems may be explained partly by the young person's self-concept. The relationship between mental health problems and subsequent psychotic experiences may be explained partly by conflict between the young person and their primary caregiver.