Evaluation of Motivational Interviewing to Improve Psychotropic Medication Adherence in Adolescents

Medication adherence rates in adolescents are poor. The World Health Organization identified that those at greatest risk were nonwhite adolescents with depression. Medication nonadherence results in poorer mental health outcomes.

The first aim of the study was to investigate if two motivational interviewing (MI) sessions would improve medication adherence in adolescents taking antidepressants and mood stabilizers. The second aim was to evaluate if attitudes toward medication correlated with adherence. The third aim was to determine if self-reported adherence scores were similar to electronic adherence data collected.

The quasi-experimental study contained an MI intervention, including a baseline and postintervention assessment of adherence over 30 days. A total of 48 adolescents, ranging in age from 12 to 18 years, were recruited from a university mental health center to participate in the study; 41 completed the study. Four nurse practitioners and two child psychiatrists mastered the MI techniques evaluated with standardized measures. The Medication Electronic Monitoring System (MEMS) was the primary measure of medication adherence. The Drug Attitude Inventory (DAI) was used as a secondary measure. Finally, participants completed the client evaluation of MI and a satisfaction survey of MI.

At endpoint, 70.7% of the participants were taking their medications between 80% and 100% of the time, as measured over 30 days, compared with 43.9% of participants at baseline. Mean adherence scores significantly improved by 17% after two MI sessions. Mean baseline adherence scores were 63.7%, whereas mean endpoint adherence scores were 80.6% (p < 0.0001). The effect size was 0.65, demonstrating moderate effect. Participants (n = 29) who demonstrated 80% or greater adherence had DAI mean scores of 16.48, whereas those below 80% had a DAI mean of 15.5 (p = 0.73), demonstrating no significant difference on drug attitudes between the two groups at endpoint. DAI baseline mean scores were 14.2, whereas endpoint mean scores were 16.2. There was a significant difference between self-rated adherence and objective data collected from the MEMS caps as participants over-reported medication adherence by an average of 18.4% at baseline (t = 6.84, df = 40, p < 0.001). Participants reported a high degree of satisfaction with MI.

MI is a promising intervention for adolescents to improve psychotropic medication adherence.