Custom Search


Monday 01 May 2006

Assessing medication effects in the MTA study using neuropsychological outcomes.

By: Epstein JN, Conners CK, Hervey AS, Tonev ST, Arnold LE, Abikoff HB, Elliott G, Greenhill LL, Hechtman L, Hoagwood K, Hinshaw SP, Hoza B, Jensen PS, March JS, Newcorn JH, Pelham WE, Severe JB, Swanson JM, Wells K, Vitiello B, Wigal T; MTA Cooperative Study

J Child Psychol Psychiatry 2006 May;47(5):446-56

BACKGROUND: While studies have increasingly investigated deficits in reaction time (RT) and RT variability in children with attention deficit/hyperactivity disorder (ADHD), few studies have examined the effects of stimulant medication on these important neuropsychological outcome measures. METHODS: 316 children who participated in the Multimodal Treatment Study of Children with ADHD (MTA) completed the Conners' Continuous Performance Test (CPT) at the 24-month assessment point. Outcome measures included standard CPT outcomes (e.g., errors of commission, mean hit reaction time (RT)) and RT indicators derived from an Ex-Gaussian distributional model (i.e., mu, sigma, and tau). RESULTS: Analyses revealed significant effects of medication across all neuropsychological outcome measures. Results on the Ex-Gaussian outcome measures revealed that stimulant medication slows RT and reduces RT variability. CONCLUSIONS: This demonstrates the importance of including analytic strategies that can accurately model the actual distributional pattern, including the positive skew. Further, the results of the study relate to several theoretical models of ADHD.

Use of this site is subject to the following terms of use