Rest-activity rhythm across the clinical spectrum of depression among adolescents

Rest-activity rhythm (RAR) disruptions are implicated in adults with major depressive disorder (MDD), but their roles in adolescent MDD and subclinical depressive presentations remain unclear. This study examined RAR parameters in adolescents varying in depression burden.

148 Chinese adolescents aged 12-18 were classified into three groups based on structured diagnostic interview: MDD (n = 59), subthreshold depression (n = 30), and healthy controls (n = 59). Adolescents completed a 14-day actigraphy assessment of physical activity, sleep, circadian amplitude and regularity, alongside depressive symptom ratings. RAR parameters were examined across groups and in relation to depressive symptoms.

Adolescents with MDD showed significantly later sleep onset (p = .020) and a lower sleep regularity index (p < .001) than controls. The subthreshold depression group demonstrated significantly later sleep onset than controls (p = .034), but had sleep regularity comparable to controls and significantly higher than the MDD group (p = .029). Lower sleep regularity was significantly associated with greater depressive symptom severity (p < .001). Findings for gross motor activity and minutes spent on moderate-to-vigorous physical activity varied by day type and by whether depression was examined using group-based or dimensional approaches.

Adolescent depression was associated with disrupted RAR. Later sleep onset was evident in clinical and subclinical depression, whereas sleep irregularity was most pronounced in clinical depression. These findings support the potential utility of targeting sleep-related disruptions in adolescent depression prevention and management. Findings of physical activity suggest that activity interventions may benefit from considering weekday-weekend variation.