Abstract Introduction Among people with serious mental illness (SMI; schizophrenia and other psychotic disorders or bipolar disorder), insomnia is strongly associated with functional difficulties including worsening mood states, mania, delusions, hallucinations, and disorganized thinking. Insomnia is among the strongest predictors of psychosis onset or relapse for those with both chronic and first-episode psychosis. Poor sleep quality, a core feature of chronic insomnia, predicts dissatisfaction with social relationships, daily activities, emotional functioning, and quality of life. Chronic insufficient sleep causes deficits in cognitive functioning generally, which are exacerbated in SMI. Little is known about how various sleep parameters predict psychotic symptoms and whether these relationships are mediated by functional deficits. We collected data from 63 Veterans with SMI and insomnia and assessed (1) core features of psychiatric symptomatology, (2) sleep parameters from self-report, actigraphy, and sleep diaries, and (3) measures of functioning. Methods The sample was N=63 Veterans with SMI. Measures included the Specific Psychotic Experiences Questionnaire, MATRICS Cognitive Consensus Battery, 14-day sleep parameters computed from participant-completed Consensus Sleep Log-Core diaries, 14-day actigraphy measured sleep parameters, and the Pittsburgh Sleep Quality Index. Results There was a significant relation between psychotic experiences and processing speed (r=-.38, p=.002), but with no other dimension of cognitive functioning. There was a trend for higher actigraphy-assessed sleep latency to be associated with more severe psychotic experiences (r=.26; p=.05). Multiple Regression tested whether cognitive functioning mediated the relation between sleep quality and specific psychotic experiences. While there was no indirect effect between the sleep quality and psychotic experiences via cognitive functioning (Indirect Effect=.007; p=.38), the total effect of sleep quality on psychotic experiences was significant (Total Effect=.06; p=.03). Conclusion Understanding the mechanisms underlying the development and maintenance of psychosis and cognition in people with SMI is critical to developing novel treatment approaches. This project illuminates the associations between cognitive functioning, sleep, and psychosis. Larger trials should use multimethod assessments to examine the potential for multiple dimensions of functioning to explain the impact of poor sleep on core features of psychiatric symptomatology. Support (if any) U.S. Department of Veterans Affairs, Rehabilitation Research and Development Service-1IK2RX001836. This information does not represent the views of the US Government.
Klingaman et al. (Fri,) studied this question.