Examining the Unified Theory of Behavior Change Constructs Among Adolescents Taking Attention-Deficit/Hyperactivity Disorder Medicine: A Longitudinal Study.

Objective: To quantitatively validate the preintention factors, behavioral intentions, and implementation factors and examine the relationships theorized by the Unified Theory of Behavior Change (UTBC) model among adolescents with attention-deficit/hyperactivity disorder (ADHD).

Methods: We conducted longitudinal analyses of data from 40 adolescents with ADHD, aged 11 to 15 years old, and their parents, including self-report of UTBC constructs using standardized measures. We collected pharmacy dispensing records for adolescents for the 4 months that followed. We used bivariate correlations to examine relationships between medication continuity, behavioral intentions, preintention factors, and the implementation factors. We conducted paired sample t-tests to compare adolescent and parent responses on UTBC items.

Results: Adolescents (mean [standard deviation {SD}] age = 13.3 [1.2] years, 75% male, 77.5% non-Hispanic Black, 90% publicly insured) reported a mean total ADHD symptom score = 29.8/54 (SD = 10.94) and mean total impairment score = 18.7/52 (SD = 10.90) and had a mean percentage of days covered with medicine over 4 months = 0.21 (range = 0-0.97). Adolescent intention to take ADHD medicine every school day was significantly related to adolescents' subsequent medication continuity (r = 0.37, P < .05). Adolescent self-concept/image and confidence taking ADHD medicine were the most important factors related to the intention to take ADHD medicine every school day. Adolescents reported less belief and intention to take ADHD medicine and more barriers to taking ADHD medicine compared to their parents.

Conclusion: The UTBC model shed light on factors related to subsequent medication use, providing a plausible mechanism for additional research to intervene to promote future medication continuity.