A small cross-sectional study published in PLOS ONE suggests that factors other than medication may contribute to excessive sleepiness in patients with psychosis. Low activity levels and insomnia may also play a role.

Researchers focused on subgroups from a previous sleep disorder study. Participants were 18 to 30 years of age, were diagnosed with nonaffective psychotic disorder, and received care from the National Health Service (NHS) mental health teams.

Participants were asked to complete a sleep diary for 7 days. Average completion was 5.5 days. A wrist-based activity monitoring device measured physical activity. The researchers used various questionnaires to assess quality of life, psychiatric symptoms, sleepiness, and fatigue.

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Participants in both the excessive sleepiness (n=14) and the control groups (n=46) reported sleeping more than 9 hours per night. The excessive sleepiness group had a higher ratio of insomnia (71.4% vs 43.4%) and nightmares (64.3% vs 43.4%) than the control group. Differences in depression, quality of life, cognitive disorganization, and paranoia were not statistically significant.

One limitation of this study was the lack of direct hypotheses concerning the impact of excessive sleepiness. Results were not corrected for multiple testing. Among other issues, naps may have been underreported.

The researchers conclude, “These issues deserve further investigation, ideally with longitudinal or experimental study designs to establish the direction of the effects amongst mood, sleep disorders, activity, medication, and psychotic symptoms.”


Reeve S, Sheaves B, Freeman D. Excessive sleepiness in patients with psychosis: An initial investigation. PLOS ONE. 2021;16(1): e0245301. doi:10.1371/journal.pone.0245301