Three-Year Effects of Motivational Interviewing-Enhanced Behavior Therapy for Adolescents With ADHD: A Randomized Community-Based Trial.

OBJECTIVE This study reports three-year effects of a parent-teen cognitive/behavioral treatment for adolescent ADHD, blended with Motivational Interviewing (Supporting Teens' Autonomy Daily; STAND), versus Usual Care (UC) in four community clinics. METHOD A randomized clinical trial with double randomization of adolescents and therapists to STAND vs. UC. Participants were 278 culturally-diverse adolescents diagnosed with DSM-5 ADHD and 82 community therapists. Long-term effects on outcomes and theorized mechanisms were assessed ∼3 years post-baseline (M age=16.94, SD=1.69): ADHD severity (parent-rated), parent-teen conflict (parent/adolescent-rated), organization, time management, and planning skills (OTP; parent-rated), treatment and school enrollment (parent/adolescent-reported), and ADHD diagnostic persistence (clinician-determined). Therapist licensure was examined as a treatment moderator. Intent-to-treat (ITT) and per protocol analyses (n=225; participants initiating treatment after agency intake) were conducted. RESULTS As in the original trial, ITT analyses indicated no long-term group x time effects. However, STAND (versus UC) led to superior long-term outcomes when therapists were licensed (22% of sample) vs. unlicensed for parent-rated hyperactivity/impulsivity: d=.39; adolescent-rated parent-teen conflict: d=.27, and parent-rated OTP skills: d=.79. Previously-reported post-treatment group differences on medication engagement were non-significant at three-year follow-up. CONCLUSION Although STAND did not outperform UC overall, group x licensure interactions indicate specific long-term impacts on ADHD symptoms, executive function skills such as OTP, and parent-teen conflict, extending this trial's acute effects and replicating previous findings. Clinicians in community settings might recommend adjunctive cognitive/behavioral treatment to adolescents with ADHD to maximize long-term outcomes. However, additional efforts are needed to facilitate effective implementation by unlicensed clinicians.