24-Hour Rest-Activity Rhythm in Middle-Aged and Older Persons with Depression.

Area of Science:

• Chronobiology
• Geriatric Psychiatry
• Wearable Technology

Background:

• Clinical observations note altered rest-activity patterns in depression.
• The specific links between depression symptoms and quantifiable 24-hour rest-activity rhythm (RAR) components are not well-established.
• Understanding these links can inform objective assessment of depression.

Purpose of the Study:

• To investigate the association between symptoms of depression and 24-hour RAR components in middle-aged and older adults.
• To identify specific RAR parameters measurable by wearable devices that correlate with depression severity.

Main Methods:

• A cross-sectional study involving 29 individuals with depression and 30 healthy controls.
• Participants wore an Actiwatch Spectrum Plus device for seven days to measure RAR parameters: inter-daily stability (IS), intra-daily variability (IV), relative amplitude (RA), M10, and L5.
• Binomial regression analysis was used to assess associations between depression symptoms and RAR components.

Main Results:

• Symptoms of depression were significantly associated with higher inter-daily stability (IS) (OR, 1.20; 95% CI, 1.01-1.44; p=0.04).
• Depression symptoms were also significantly associated with lower average physical activity during the most active 10-hour span (M10) (OR, 0.85; 95% CI, 0.74-0.96; p=0.01).

Conclusions:

• Findings suggest that a more stable 24-hour rest-activity rhythm and reduced daytime activity are potential objective markers associated with depression in middle-aged and older adults.
• Wearable technology offers a promising avenue for quantifying these rhythm disturbances in depression assessment.