Prescription drug (PD) misuse is a challenging problem. This randomized controlled trial tested whether a brief intervention (BI) involving two sessions of motivational interviewing could reduce problematic PD use among 126 inpatients at a German university hospital. Problematic use was defined as having a prior diagnosis of prescription drug dependence or abuse or as taking nonprescribed potentially addictive medication for at least 60 of the 90 days preceding baseline screening.

The first session of the intervention was conducted while the patients were hospitalized; the second took place four weeks later. A prior report, described in the March–April 2009 issue of this newsletter, showed a reduction in PD use at 3 months following the intervention. This study examined two outcomes — cessation of PD use and 25% reduction in use — at 12 months. Analyses controlled for baseline differences in PD dependence and duration of use.

• There was no difference in cessation rates between the BI and control groups at 12 months (25% versus 20%; odds ratio [OR], 1.4).
• There was no difference in proportion of patients who reduced their drug use by at least 25% at 12 months (50% versus 49%; OR, 0.9).

Comments by Michael Levy, PhD
It is not surprising that BI had no lasting effect on PD use at 12 months given that the effects of BI often wear off over time and that patients in this study had PD abuse or dependence or had been using nonprescribed drugs almost daily prior to screening. These results suggest that, while BI may demonstrate short-term effects, sustained changes may require ongoing care or more intensive intervention.