Physical activity, psychological distress, perceived stress, and sleep quality in people with schizophrenia and depression: A descriptive cross-sectional study

Background: People with mental illness often experienced sleep disturbances. Physical activity and psychological factors may be associated with sleep quality among people with mental illness. Aim: The purpose of this study was to assess the association between physical activity (PA), psychological distress, perceived stress, and sleep quality in people with mental illness. Methods: Sixty-seven people with schizophrenia, major depressive disorder, and dysthymia were enrolled in the study group. All participants completed the International PA Questionnaire, Kessler psychological distress Scale, the Perceived Stress Scale, and the Pittsburgh Sleep Quality Index (PSQI). Results: The results revealed that moderate metabolic equivalent task (MET)-minutes/week (min/wk) and psychological distress accounted for 39% of the variance in subjective sleep quality. Walking MET-min/wk and psychological distress accounted for 24% of the variance in the use of sleep medication. Vigorous MET-min/wk, psychological distress, and perceived stress accounted for 42% of the variance in daytime dysfunction over the previous month. Psychological distress was a significant related factor for sleep duration (adjusted R[2] = 0.20) and sleep disturbances (adjusted R[2] = 0.33), respectively. A majority of the participants (n = 58, 87%) used sleep medication and most (91%) of them had PSQI ≥5, which was suggestive of sleep problems. Conclusion: Our results indicated that PA, psychological distress, and perceived stress could have impact on different aspects of sleep quality. More research is needed to explore the association between these variables on sleep quality in people with mental illness.