People at high risk of developing psychosis report greater sleep disturbances, which are associated with severity of attenuated psychotic symptoms, specifically symptoms of paranoia and hallucinations, according to a review published in Psychiatry Research.
The investigators of this study examined associations between sleep problems, attenuated psychotic symptoms (eg, subclinical hallucinations, delusions, grandiosity), and clinical outcomes in a large sample of young people at clinical high risk (CHR) for psychosis.
The study sample included 1020 people aged 12 to 30 years, of which 740 participants met CHR criteria for psychosis and 280 participated as healthy controls. All participants completed the Structured Interview for Psychosis-Risk Syndromes (SIPS) across 4 symptom domains (positive, negative, disorganized, and general). The SIPS was administered at 6, 12, 18, and 24 months. Participants were rated from 0 to 6 on the Scale of Prodromal Symptoms and CHR status was based on severity of positive symptoms including: “symptomatic” (positive symptoms scores between 3 and 5 with no changes in severity), “prodromal progression” (positive symptoms scores between 3 and 5 with an increase in severity), “converted” (meeting criteria for a psychotic disorder), or “in remission” (scores of 2 or less on each positive symptom item). Sleep disturbance was measured under the general symptom domain and rated from 0 to 6 based on severity of the reported sleep problem. Analysis of covariance was used to compare severity of sleep disturbances between the CHR and control groups, and linear regression analyses were used to examine associations between baseline sleep problems and total positive symptom severity.
Among CHR participants, sleep disturbances were found to be positively associated with attenuated psychotic symptom severity; baseline sleep problems were similar among the 4 clinical outcome groups (symptomatic, prodromal progression, converted, remission). After correcting for multiple comparisons, sleep disturbances were associated with 2 specific attenuated psychotic symptoms: suspiciousness/paranoia and perceptual abnormalities/hallucinations. Although depression had no mediating effect on the association of sleep disturbances and total attenuated psychotic symptoms, an indirect effect was shown on a relationship between sleep problems and paranoid symptoms only.
A limitation of the study included that sleep disturbances were assessed with a single item (primarily self-report) using the same scale used to measure attenuated psychotic symptoms. Chronicity of sleep disturbances was also not assessed; therefore, differences between limited bouts of insomnia vs long-term chronic insomnia could have affected clinical outcomes. Additionally, the cross-sectional design of the study limited ability to assess directionality of effects and mediation effects over time.
Young CHR individuals had greater sleep disturbances than healthy controls, and the extent of sleep problems was associated with severity of attenuated psychotic symptoms. This study adds to current clinical knowledge on this topic by demonstrating that symptoms of paranoia and hallucinations were specifically linked to sleep disturbances, and, that depression was found to mediate the association of psychosis and sleep problems only in paranoid individuals.
Goines KB, LoPilato AM, Addington J, et al. Sleep problems and attenuated psychotic symptoms in youth at clinical high-risk for psychosis. [published online August 3, 2019]. Psychiatry Res. doi: 10.1016/j.psychres.2019.112492