The primary goal of Motivational Interviewing for Opioid Use Disorder (MI-OUD) is to reduce patient opioid use and opioid-related consequences. There are no studies that suggest that MI-OUD alone or MI-OUD in combination with medication for opioid use disorders leads to reduced opioid use; however, one pilot trial of non-medical opioid users admitted to the emergency department suggested that MI-OUD could reduce patient overdose behaviors. Studies have also provided mixed results on whether Motivational Interviewing for Substance Use Disorder (MI-SUD) leads to lower rates of inpatient readmission. One study found that MI-SUD reduced hospital admissions relative to a standard control, whereas another study found that MI-SUD did not statistically differ from the control condition.

A number of studies suggest that although Motivational Interviewing for Opioid Use Disorder (MI-OUD) may not reduce opioid use, MI-OUD may lead to greater mental health outcomes and quality of life for opioid users. In a trial of cognitive behavioral therapy (CBT) in combination with MI-OUD, patients reported improved symptoms of somatization, obsessive-compulsive disorder, anxiety, phobic anxiety, paranoid ideation, and psychoticism. Patients also reported fewer physical or emotional limitations after MI-OUD than with treatment as usual, suggesting that the intervention may reduce symptoms and improve quality of life.