A three-session motivational interviewing (MI) intervention effectively decreased hazardous drinking among patients with depression, although it did not impact cannabis use or depression symptoms. These findings contribute to the literature on MI in psychiatric populations, suggesting it may be associated with better mood status, lower re-hospitalization rates, and improved adherence to treatment plans. Furthermore, the study highlights the need for further research on the relationship between depression severity and hazardous drinking, and suggests that depression treatments should incorporate services aimed at reducing alcohol use.