Receives Indigenous Recovery Planning (IRP) intervention, which includes 6 weekly group intervention sessions lasting about 2 hours each.

Participants in the waitlist control group do not receive the intervention until after treatment group completes the intervention. Outcomes will be compared between the 2 study arms at baseline and at follow-up, at which point the treatment group will have completed the intervention and the waitlist control group will have not yet been exposed to the intervention, thereby serving as the control group.

The Indigenous Recovery Planning (IRP) intervention consists of a 6-week group-based intervention. Each of the 6 weekly sessions is delivered by a community member facilitator. Facilitators lead the group through a series of culturally adapted relapse prevention exercises designed to change their substance use.

Focus areas for the 6 sessions are: 1) introduction and goal setting; 2) relapse and recovery; 3) craving, mindfulness, and self-compassion; 4) coping with trauma and stress; 5) enlisting social support for recovery; 6) envisioning and planning for the future.

Percent days absent will be measured using the Timeline Followback (TLFB), a widely used calendar-based recall instrument shown to yield valid and reliable estimates of substance use behavior. Additional analyses will be conducted with other variables derived from TLFB data, including number of drinks per drinking day, percent heavy drinking days, and percent drug use days.

Measured by the Drinker Inventory of Consequences, modified for alcohol and drug use

Measured by the World Health Organization Brief Quality of Life Scale