Predictors of Relapse in Major Depressive Disorder (PERFORM-D)

This study is a multi-centre prospective naturalistic observational cohort study. Participants with MDD in remission will be enrolled and followed for 18 months since enrollment. This study will be conducted across eight Canadian clinical-academic sites (Vancouver, Calgary, Hamilton, Toronto Western Hospital, Toronto-Center for Addiction and Mental Health \[CAMH\], Kingston, Ontario Shores and Halifax), which are currently enrolling participants for the OPTIMUM-D study (NCT05017311). For the present study, participants will be recruited from each of these sites, focusing on OPTIMUM-D participants who attain broadly-defined remission. Participants will wear a GENEActiv accelerometer (Activinsights; motion tracker) on the non-dominant wrist for the duration of the study. Participants will rate their depression by completing the Quick Inventory of Depressive Symptoms 16-item Self-Rated Version (QIDS-16SR) and anxiety by completing the Generalized Anxiety Disorder 7-item (GAD-7) at weekly interval throughout the study. Participants will have in-person follow-up assessments every two months to rate their depressive symptom severity using the Montgomery-Asberg depression Rating Scale (MADRS). Speech and Electroencephalography (EEG) will be collected every two months, and at the time of relapse.