Which social environment is more important in the persistence of psychotic experiences? Differential impact of neighbourhood and family context in a six-year longitudinal population-based cohort

Introduction Social environment may lead to emergence and persistence of psychotic experiences. Objectives Testing differential impact of social environments on emergence and persistence of subclinical psychotic experiences. Aims To assess different social environments that predicts emergence and persistence of subclinical psychotic experiences in a 6-year follow-up of a representative general population sample. Methods A longitudinal prospective cohort study (the TurkSch - The Izmir Mental Health Survey for Gene-Environment in Psychoses) was conducted with a general population sample ( n =4011) from Izmir-Turkey, who were 15-64 years of age at baseline. Sociodemographic factors, social environmental exposures (deprivation and social capital of neighbourhoods, and familial dysfunction and relationships), and measures of psychopathology (subclinical psychotic experiences) were assessed across two waves (T 1 -2008 and T 2 -2014; n =2192) using the Composite International Diagnostic Interview. Results Measures of wider social environment at T 1 (high social control and social deprivation within neighbourhoods) was associated with emergence (OR=1.6; 95% CI=0.6-2.4) and persistence (OR=1.8; 95% CI=0.6-2.4) of psychotic experiences at T 2 . Also, measures of familial dysfunction and relationships were associated with emergence (OR=2.1; 95% CI=1.2-3.3) and persistence (OR=3.3; 95% CI=1.4-6.7) at T 2 . The associations between wider social environment and psychotic experiences were not significant after adjusting for measures of family dysfunction relationship. Conclusions The association between wider social environment and psychosis may be partially a result of dysfunctional relationships within the narrow environment including family. Current and past difficult family relationships may be an important contributing factor.