Researchers from Tianjin Medical University, Hangzhou Normal University, Tianjin University of Traditional Chinese Medicine, and the National Institute of Health Data Science at Peking University have published a longitudinal study in Health Data Science using UK Biobank accelerometry data to examine objectively measured rest-activity timing phenotypes and incident major depressive disorder (MDD) and anxiety disorders. Compared with a daytime-active group, a night-active group had higher risks of both outcomes, whereas an early-morning-active phenotype was associated with lower MDD risk.
Self-reported chronotype can be affected by reporting bias. The team used 24-hour accelerometer activity patterns as an objective behavioral proxy for timing phenotype, assessed associations with subsequent mental-health outcomes, and explored links with brain magnetic resonance imaging (MRI) measures.
The study included 94,344 UK Biobank participants free of MDD and anxiety disorders with valid accelerometry data. Investigators used k-means clustering to classify 24-hour activity phenotypes and Cox models to estimate risks. Over a median follow-up of 6.8 years, they identified 2,361 MDD cases and 2,278 anxiety cases. Compared with the daytime-active group, the night-active group had hazard ratios of 1.30 (95% CI, 1.15 to 1.48) for MDD and 1.27 (95% CI, 1.11 to 1.45) for anxiety disorders. The early-morning-active group had a 19% lower MDD risk (95% CI, 8% to 29%). Higher physical activity from 00:00 to 04:59 was adversely associated with both outcomes, whereas higher activity from 06:00 to 08:59 was favorably associated. In MRI analyses of 17,571 participants, the night-active group was associated with lower white-matter, gray-matter, frontoparietal-gray-matter, and subcortical volumes.
The findings provide longitudinal observational evidence and exploratory imaging clues about activity timing and mental health. They do not show that changing activity timing reduces risk; the authors note that randomized controlled trials are needed to test whether modifying timing can prevent mental disorders.
Health Data Science
Rest–Activity Timing Phenotypes and Mental Health: A Longitudinal Analysis of 24-Hour Accelerometry in Population-Based Cohorts
3-Mar-2026