Introduction Subthreshold depression is prevalent in general population and is associated with poorer quality of life, higher health care use and increased risk of mental disorders mainly depression. Objectives Testing predictive impact of subthreshold depression on emergence and persistence of subclinical psychotic experiences. Aims To assess association between subthreshold depression 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, subthreshold depression (based on responses to systematic screening questions of the relevant questions with having less than five symptoms or having symptoms less than two weeks or having non-interfering impairment due to symptoms), 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 Prevalence estimates of subthreshold depression at T 1 and persisted psychotic experiences were 4.2% and 8.3%, respectively. Subthreshold depression at T 1 was associated with persistence (OR=1.6; 95% CI=0.6–2.9) of psychotic experiences at T 2 . Conclusions Psychosis may be a poor outcome of subthreshold extended phenotypes in the general population with early expression of sets of symptoms blending from depressive, anxious and psychotic states. Assessing the early dynamics of symptoms that affect each other over time may facilitate the understanding of the dynamic circuit of early psychopathology.
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