This study is on a type of psychotherapy to treat depression in older adults called Cognitive Behavioural Therapy (CBT-OA). CBT is based on the idea that changing thoughts and behaviours can improve mood. CBT has been shown to treat depression in many types of people. CBT-OA changes the usual approaches used for older adults and offers the therapy in a group settings for 8 weeks, for 2 hours a week.

Participants will be randomly (by chance) placed into one of two study groups. One group will receive CBT-OA treatment right away. The other group (Treatment As Usual) will receive standard care from their doctor during the 12-week study period. Both groups will be closely monitored during the study period. The standard care group will be offered CBT-OA in a future session outside of the study.

Inclusion Criteria:

• Ambulatory patients 65+ years of age and diagnosed with MDE per DSM-V criteria by a geriatric psychiatrist using a standard clinical biopsychosocial assessment and a Beck Depression Inventory (BDI) of >12.

Exclusion Criteria:

• Patients with psychosis, those undergoing acute inpatient care or electroconvulsive therapy (ECT), those with dementia (Mini-Mental Status Examination (MMSE) score of < 26), and those with chronic personality disorders