BackgroundDespite evidence in scientific literature indicating the effectiveness of both cognitive behavioral therapy (CBT) and physical exercise in the management of major depressive disorder (MDD), few studies have directly compared them.ObjectiveThis study aims to evaluate and compare the effectiveness of group CBT, physical exercise, and only wait-listing to receive treatment-as-usual (TAU) in the management of MDD. The investigators hypothesize that participants with MDD assigned to the group CBT or exercise arms of the study will achieve superior outcomes compared with participants wait-listed to receive TAU only.MethodsThis prospective rater-blinded randomized controlled trial assesses the benefits of group CBT and exercise for participants with MDD. A total of 120 patients with MDD referred to addiction and mental health clinics in Edmonton, Canada, will be randomly assigned to one of the three equal-sized arms of the study to receive either weekly sessions of group CBT plus TAU, group exercise three times a week plus TAU, or only TAU for 14 weeks. Participants will be assessed at enrollment, 3 and 6 months post enrollment, midtreatment, and upon treatment completion for primary (functional and symptom variables) and secondary outcomes (service variables and health care utilization). In addition, participants in the intervention groups would be evaluated weekly with one functional measure. The data will be analyzed using repeated measures and effect size analyses, and correlational analyses will be completed between measures at each time point.ResultsThe study will be conducted in accordance with the Declaration of Helsinki (Hong Kong amendment) and Good Clinical Practice (Canadian guidelines). Written informed consent will be obtained from each subject. The study received ethical clearance from the Health Ethics Research Board of the University of Alberta on September 7, 2018 (Pro 00080975) and operational approval from the provincial health authority (Alberta Health Services 43638). As of October 13, 2019, we have enrolled 32 participants. The results will be disseminated at several levels, including patients, practitioners, academics, researchers, and health care organizations.ConclusionsThe results of the pilot trial may inform the implementation of a multicenter clinical trial and provide useful information for administrators and clinicians who are interested in incorporating group CBT and group exercise interventions into existing care.Trial RegistrationClinicalTrials.gov NCT03731728; https://clinicaltrials.gov/ct2/show/NCT03731728International Registered Report Identifier (IRRID)PRR1-10.2196/14309