Factors Influencing Medication Adherence in Adolescents with Psychiatric Disorders: Quantitative Results from a Multicenter Mixed-Methods Study.

BACKGROUND: Medication-related attitudes are considered an important determinant of adherence to psychopharmacological treatment in adolescents. The Questionnaire on Attitudes Toward Treatment (QATT) was originally developed for adolescents with attention-deficit/hyperactivity disorder, but its applicability in transdiagnostic adolescent psychiatric populations has not been investigated. This study examined medication attitudes and factors associated with noncomplete medication adherence in a transdiagnostic sample of adolescents receiving psychopharmacological treatment. METHODS: This secondary analysis included 75 adolescents (12-17 years) participating in the multicenter SEMA study (Subjective Experience and Medication Adherence in Adolescents with Psychiatric Disorders). Medication adherence was assessed using the Medication Adherence Report Scale (MARS) and the QATT, together with demographic and clinical variables. Adherence was classified as complete or noncomplete. Group comparisons of QATT scores and an exploratory multivariable logistic regression were performed to identify factors associated with noncomplete medication adherence. RESULTS: Forty percent of participants were classified as not completely adherent. Higher QATT scores, indicating less favorable attitudes toward medication, were observed among older adolescents, inpatients, adolescents with internalizing disorders, and participants classified as not completely adherent. In the multivariable logistic regression, higher QATT total scores (odds ratio [OR] = 1.05, 95% confidence interval [CI]: 1.00-1.10; p = 0.048) and polypharmacy (OR = 3.64, 95% CI: 1.03-12.88; p = 0.046) were independently associated with noncomplete medication adherence. CONCLUSION: In this transdiagnostic adolescent psychiatric sample, less favorable medication attitudes, as assessed by the QATT, were associated with noncomplete medication adherence. Assessing medication attitudes may complement routine adherence assessment. Prospective studies are needed to further validate the QATT and determine its utility for identifying adolescents at risk of noncomplete medication adherence.