Methylphenidate dosage for children with ADHD over time under controlled conditions: lessons from the MTA

To examine the trajectory of methylphenidate (MPH) dosage over time, following a controlled titration, and to ascertain how accurately the titration was able to predict effective long-term treatment in children with attention-deficit/hyperactivity disorder (ADHD).

Using the 14-month-treatment database of the NIMH Collaborative Multisite Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder (MTA), the outcome of the initial placebo-controlled, double-blind, randomized daily switch titration of MPH was compared with the subsequent maintenance pharmacotherapy. Children received monthly monitoring visits and, when needed, medication adjustments.

Of the 198 children for whom MPH was the optimal treatment at titration (mean +/- SD dose: 30.5 +/- 14.2 mg/day), 88% were still taking MPH at the end of maintenance (mean dose 34.4 +/- 13.3 mg/day). Titration-determined dose and end-of-maintenance dose were significantly correlated (r = 0.52-0.68). Children receiving combined pharmacotherapy and behavioral treatment ended maintenance on a lower dose (31.1 +/- 11.7 mg/day) than did children receiving pharmacotherapy only (38.1 +/- 14.2 mg/day). Of the 230 children for whom titration identified an optimal treatment, 17% continued both the assigned medication and dosage throughout maintenance. The mean number of pharmacological changes per child was 2.8 +/- 1.8 (SD), and time to first change was 4.7 months +/- 0.3 (SE).

For most children, initial titration found a dose of MPH in the general range of the effective maintenance dose, but did not prevent the need for subsequent maintenance adjustments. For optimal pharmacological treatment of ADHD, both careful initial titration and ongoing medication management are needed.