Building Recovery By Improving Goals, Habits, and Thoughts

The investigators will investigate whether group Cognitive Behavioral Therapy (CBT) for depression, with alcohol and other drug (AOD) treatment counselors leading the groups, is effective and cost effective in treating depression. If so, it could substantially increase access to appropriate mental health care. 360 clients with Beck Depression Inventory-II scores \> 17 who are being treated in a single public sector AOD treatment organization will receive one of two conditions: (1) usual care residential AOD treatment (UC); (2) usual care AOD residential treatment plus a 16-session course of group CBT delivered by trained AOD counselors (CBT). Data will be analyzed using an intent-to-treat model. The investigators will collect data on the service-level costs and health effects associated with UC and CBT, and will calculate the incremental cost per unit of depression and AOD improvement, compared to UC.