Researchers found that patients with major depressive disorder have reduced physical activity, fragmented activity patterns, lower circadian rhythm amplitude, and delayed timing of sleep and peak activity.

The study published in JAMA Psychiatry analyzed data from 2,317 adults (1164 without major depressive disorder (MDD), 185 with current MDD, and 968 with remitted MDD), and aimed to delineate how sleep, physical activity, and circadian rhythms correlated with current or remitted MDD.

The researchers employed the Joint and Individual Variation Explained method to analyze wrist-worn accelerometry data collected over 2 weeks, allowing the identification of both joint and individual components within the accelerometry domains. The joint components, reflecting the overlap among sleep, physical activity, and circadian rhythms, were more pronounced than individual variations. These components accounted for 58.5%, 79.5%, and 54.5%, respectively, of the total variation in the domains.

Key findings revealed that patients with MDD exhibited reduced and more fragmented physical activity, lower circadian rhythm amplitude, delayed timing of sleep, and peak physical activity. These patterns were observed in both current and remitted MDD cases, indicating that dampened circadian rhythmicity may serve as a trait marker for the disorder.

Accelerometry can characterize 24-hour rhythms in relation to MDD. The researchers highlighted the importance of considering the entire sleep-wake cycle in future studies to develop targeted interventions for MDD.

This study was supported by grants from the U.S. National Institute of Mental Health and other institutions. The authors reported no conflicts of interest.