Clinical relevance of the primary findings of the MTA: Success rates basedon severity of ADHD and ODD symptoms at the end of treatment

Objectives: To develop a categorical outcome measure related to clinical de cisions and to perform secondary analyses to supplement the primary analyse s of the NIMH Collaborative Multisite Multimodal Treatment Study of Childre n With Attention-Deficit/Hyperactivity Disorder (MTA). Method: End-of-treat ment status was summarized by averaging the parent and teacher ratings of a ttention-deficit/hyperactivity disorder and oppositional defiant disorder s ymptoms on the Swanson, Nolan, and Pelham, version IV(SNAP-IV) scale, and l ow symptom-Severity ("Just a Little") on this continuous measure was set as a clinical cutoff to form a categorical outcome measure reflecting success ful treatment. Three orthogonal comparisons of the treatment groups (combin ed treatment [Comb], medication management [MedMgt], behavioral treatment [ Beh], and community comparison [CGI) evaluated hypotheses about the MTA med ication algorithm ("Comb + MedMgt Versus Beh + CC"), multimodality superior ity ("Comb versus MedMgt"), and psychosocial substitution ("Beh versus CC") . Results: The summary of SNAP-IV ratings across sources and domains increa sed the precision of measurement by 30%. The secondary analyses of group di fferences in success rates (Comb = 68%; MedMgt = 56%; Beh = 34%; CC = 25%) confirmed the targe effect of the MTA medication algorithm and a smaller ef fect of multimodality superiority, which was now statistically significant (p <.05). The psychosocial substitution effect remained negligible, and non significant. Conclusion: These secondary analyses confirm the primary findi ngs and clarify clinical decisions about the choice between multimodal and unimodal treatment with medication.