Participants will be excluded if they are receiving corticosteroids or antihypertensive medications; misused substance or alcohol in the past 3 months; received electroconvulsive therapy in the last 1 year; or have a neurological or medically unstable condition. Another exclusion criterion includes the inability to provide written informed consent. The Montgomery-Asberg Depression Rating Scale (MADRS) and Hamilton Depression Rating Scale 17-Item (HAM-D-17) will be administered at baseline and weekly throughout the 8 weeks of treatment assignment. Participants who are actively suicidal or evaluated as being a suicide risk will also be excluded. Other reasons for discontinuation are impaired fasting glucose (i.e., 6.1 - 6.9 mmol/L), and non-compliance (i.e., failure to administer ≥ 80% of the assigned treatment in any week).