Early trauma and familial risk in the development of the extended psychosis phenotype in adolescence
Objective: Both genetic and environmental factors are thought to play a role in the development of psychotic outcomes; however, their respective contributions over time, including possible developmental interactions, remain largely unknown. Method: The contribution of parental general and psychotic psychopathology as proxies of genetic risk to the development of subthreshold psychosis and its hypothesized interaction with childhood trauma were studied in a general population sample of 2230 adolescents, followed from age 10-16years. Outcome measures were: i) level of psychotic experiences at age 16years and ii) persistence of such experiences over the total follow-up period. Results: General parental psychopathology was associated with CAPE score (OR=1.08; P<0.043 for highest quintile) and suggestively predicted psychosis persistence (OR, 1.16; P<0.072). Psychotic parental psychopathology was suggestively associated with CAPE score (OR, 2.25; P<0.063 for highest quintile), predicted membership of the Persistent group (OR, 3.72; P<0.039) and suggestively predicted membership of the Decreasing group (OR 2.04; P<0.051). Childhood trauma was associated with CAPE score and with all developmental trajectories of subclinical psychosis. No evidence was found for an interaction between trauma and parental psychopathology. Conclusion: The development and persistence of subthreshold psychotic symptoms may be conditional on non-interacting proxy genetic and environmental influences.