Temporal associations between sleep quality and paranoia across the paranoia continuum: An experience sampling study.

Sleep disturbances are prevalent among individuals with a psychotic disorder and have been linked to symptoms of paranoia across the entire psychosis continuum. Emerging evidence suggests that rather than a secondary symptom, poor quality of sleep may contribute to elevated paranoid ideation. We investigated the temporal dynamics of sleep quality and paranoid ideation using the experience sampling method in 42 acutely paranoid individuals with a psychotic disorder, 32 nonparanoid individuals with psychotic disorder, and 41 individuals with high schizotypy traits. We applied time-lagged mixed multilevel modeling to tease apart the effect of poor sleep quality on morning paranoia and negative affect, and the impact of evening paranoid ideation and negative affect on subsequent sleep quality. In the whole sample, poor subjective sleep quality predicted elevated paranoia the following morning, a relationship that was fully mediated by morning negative affect. No significant association between evening paranoia and poor sleep the following night emerged. In the everyday lives of individuals on the paranoia continuum, low quality of sleep appears to drive paranoia through its impact on negative affect. These findings identify sleep quality as an important target of transdiagnostic interventions for psychotic and affective symptomatology. (PsycINFO Database Record (c) 2019 APA, all rights reserved).