Associations between rest-activity/light-exposure rhythm characteristics and depression in United States adults: A...

This cross-sectional study investigated the association between 24-hour rest-activity rhythm (RAR), light exposure rhythm (LER), and depression symptoms in American adults, using data from the National Health and Nutrition Examination Survey (2011-2014, N = 6852). RAR and LER characteristics were derived from a 24-hour activity recorder and analyzed using the extended cosine model, focusing on intradaily variability (IV), interdaily stability (IS), and relative amplitude (RA). Depression was assessed via the Patient Health Questionnaire-9 (PHQ-9).Multiple logistic and linear regression models showed that higher IV in RAR and LER were associated with increased depression risk (RAR-IV OR = 1.92 [95 % CI: 0.89-4.13]; LER-IV OR = 2.5 [1.45-4.30]), while higher IS and RA in both rhythms were linked to lower depression risk (RAR-IS OR = 0.22 [0.10-0.48], RAR-RA OR = 0.20 [0.11-0.37], LER-IS OR = 0.22 [0.10-0.49], LER-RA OR = 0.29 [0.15-0.56]). Participants in the highest tertile for IS and RA had a significantly lower depression risk compared to the lowest tertile. Subgroup analyses indicated interactions between age and RAR-IV, gender and LER-IV, and BMI and LER-RA (p-interaction < 0.05). Disruptions in RAR and LER are positively associated with depression, emphasizing the need for rhythm regulation interventions considering age, gender, and BMI factors.