A study evaluating motivational interviewing (MI) among depression patients yielded several key results:

1. Hazardous drinking and cannabis use were frequently reported.
2. Among cannabis users, participants receiving MI scored higher on a readiness-to-change scale than the control group.
3. There was no significant difference between groups in the type or number of usual psychiatric care visits at the six-month follow-up.
4. The MI intervention had no significant effect on cannabis use.
5. At three months, participants receiving MI were less likely to report hazardous drinking compared to controls.