National Institute of Mental Health Multimodal Treatment Study of ADHD follow-up: changes in effectiveness and growth after the end of treatment

Intent-to-treat analyses of the Multimodal Treatment Study of ADHD (MTA) revealed group differences on attention-deficit/hyperactivity disorder symptoms ratings, with better outcome in groups of participants who were assigned the medication algorithm-medication alone (MedMgt) and combined (Comb)--than in those who were not-behavior modification (Beh) alone and community comparison (CC). However, the effect size was reduced by 50% from the end of treatment to the first follow-up. The convergence of outcomes suggests differential changes by treatment group beween 14 and 24 months, which this report explores, both for benefits of treatment and for side effects on growth.