Testing the mediating role of negative affect, affect intolerance, and dissociation in the relationship between sleep...

Sleep disturbances are known to causally contribute to psychotic experiences, with negative affect indicated as a mediator in previous research. However, other plausible related mechanisms such as affect intolerance and dissociative experiences have not been tested. We hypothesised that sleep restriction would increase psychotic experiences, with effects mediated by increases in negative affect, affect intolerance and dissociative experiences.

A within-subjects, cross-over experimental study was conducted with 58 undergraduate participants, comparing sleep restriction (≤4 h sleep for one night) to standard sleep.

In comparison to standard sleep, one night of sleep restriction resulted in significant increases in all psychotic experiences except grandiosity, as well as significant increases in all proposed mediators. Dissociative experiences (46.2%), and combined mediators (89.1%), substantially mediated the effect of reduced sleep on paranoia. Dissociative experiences also partially mediated the effect of reduced sleep on hallucinations (38.5%). No significant mediation effects were identified for cognitive disorganisation, anhedonia or distress from psychotic experiences.

These findings extend the causal relationship between sleep loss and psychotic experiences as occurring after only one night of sleep restriction. They also identify a novel mechanism - dissociative experiences - as contributing towards both paranoia and hallucinations. Negative affect was supported as a mediating mechanism for paranoia, in line with existing research, however there was limited identification of mediating mechanisms for other psychotic experiences. The results emphasise the importance of further experimental research investigating the relationship between affective processes, particularly dissociative experiences, and specific symptoms of psychosis.