Depression and mania symptoms mediate the relationship between insomnia and psychotic-like experiences in the general population.

Psychotic-like experiences (PLEs) are subclinical forms of psychosis commonly experienced in the general population. The nature of PLEs has yet to be clearly defined, yet mood and sleep disturbances may be two predictors. Sleep disturbance increases paranoia and hallucinations in experimental studies, and insomnia is considered a longitudinal precursor of psychosis. Mood disturbances including depression and mania, which can be induced by insomnia, can also result in psychotic symptoms. However, whether insomnia may predict PLEs via the mediation of mood disturbance has yet to be fully clarified. To advance this field, the aim of this study was to investigate the mediation role of depression and mania symptoms on the relationship between insomnia and PLEs.

1.086 community members (28.32±9.04 years, 58.1% females) cross-sectionally completed self-reported measures of insomnia severity, depression/mania symptoms, and PLEs. Bivariate correlations, hierarchical multiple regressions and mediation analyses with bootstrap approach were performed. Insomnia and mood disturbances (depression/mania) were significantly associated with PLEs (β = 0.06, p < .05; β = 0.225, p < .001, respectively). Mediation analysis revealed a significant indirect effect between insomnia and PLEs mediated by mood disturbance through bootstrap approach (β=0.13, se= 0.02, 95% CI: 0.10 - 0.17). Our results support the view of insomnia and mood disturbances as predictors of PLEs in the general population and foster the replication of these findings using longitudinal designs.