Associations Between Actigraphy-Derived Sleep-Wake Patterns and Illness Trajectories and Treatment Response in Major Depressive Disorder

The proposed study will include a longitudinal ecological study (Study 1) and a randomised controlled trial (Study 2). The aims will be to (1) identify the sleep-wake profiles in individuals with MDD through clustering; (2) examine the associations between sleep-wake features/profiles and the prognosis of MDD; and (3) investigate the anti-depressant effects of sleep- and circadian-targeted intervention in those with MDD and whether sleep-wake features/profiles may moderate the treatment outcomes. 70 depressed participants from Study 1 will be randomized to Study 2 for the Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C) group and the care-as-usual (CAU) group in a 1:1 allocation ratio. The study period will be 8 weeks. Major assessments at baseline and immediate post-treatment will be managed by an independent assessor (a research assistant, RA) who is blind to the group allocation. The proposed trial and the nested pilot study will follow the CONSORT and STROBE guidelines, respectively. The intervention will be provided free of charge.The current registration is only for Study 2 of the current research project.