An intensive, 9-session motivational interviewing (IMI) intervention was assessed using a randomized clinical trial of 217 methamphetamine (MA) dependent individuals. Intensive motivational interviewing (IMI) was compared with a single standard session of MI (SMI) combined with eight nutrition education sessions. Interventions were delivered weekly over 2 months. All study participants also received standard outpatient group treatment three times per week. Both study groups showed significant decreases in MA use and Addiction Severity Index drug scores, but there were no significant differences between the two groups. However, reductions in Addiction Severity Index psychiatric severity scores and days of psychiatric problems during the past 30 days were found for clients in the IMI group but not the SMI group. SMI may be equally beneficial to IMI in reducing MA use and problem severity, but IMI may help alleviate co-occurring psychiatric problems that are unaffected by shorter MI interventions. Additional studies are needed to assess the problems, populations, and contexts for which IMI is effective.
Keywords: Methamphetamine; motivational interviewing; psychotherapy; randomized clinical trial; treatment dose.