Objective. In the Multimodal Treatment Study of ADHD (MTA), the effects of medication management (MedMgt) and behavior modification therapy (Beh) and their combination (Comb) and usual community comparison (CC) in the treatment of attention-deficit/hyperactivity disorder (ADHD) differed at the 14-month assessment as a result of superiority of the MTA MedMgt strategy (Comb or MedMgt) over Beh and CC and modest additional benefits of Comb over MedMgt alone. Here we evaluate the persistence of these beneficial effects 10 months beyond the 14 months of intensive intervention.
Methods. Of 579 children who entered the study, 540 (93%) participated in the first follow-up 10 months after the end of treatment. Mixed-effects regression models explored possible persisting effects of the MTA medication strategy, the incremental benefits of Comb over MedMgt alone, and the possible superiority of Beh over CC on 5 effectiveness and 4 service use domains.
Results. The MTA medication strategy showed persisting significant superiority over Beh and CC for ADHD and oppositional-defiant symptoms at 24 months, although not as great as at 14 months. Significant additional benefits of Comb over MedMgt and of Beh over CC were not found. The groups differed significantly in mean dose (methylphenidate equivalents 30.4, 37.5, 25.7, and 24.0 mg/day, respectively). Continuing medication use partly mediated the persisting superiority of Comb and MedMgt.
Conclusion. The benefits of intensive MedMgt for ADHD extend 10 months beyond the intensive treatment phase only in symptom domains and diminish over time.