Effects of methylphenidate treatment in children with mental retardation and ADHD: individual variation in medication response.
OBJECTIVE
Individual variation in cognitive and behavioral response to methylphenidate (MPH) was investigated in children with mental retardation and attention-deficit/hyperactivity disorder.


METHODS
Twenty-four children (mean age 10.9 years, SD = 2.4) participated in a placebo-controlled, double-blind, crossover trial with 0.15-, 0.30-, and 0.60-mg/kg b.i.d. doses of MPH. Parent and teacher behavioral ratings, as well as cognitive task performance, were assessed at each dose.


RESULTS
Relative to placebo, most children with attention-deficit/hyperactivity disorder and mental retardation showed some degree of behavioral and cognitive improvement with MPH treatment. However, fewer of these children made substantial gains (>30% improvement, relative to placebo) with MPH treatment. At the highest dose, 55% of the children showed substantial behavioral gains and 46% made substantial gains in cognitive task performance. However, there was substantial independence between changes in behavior and changes in cognitive performance.


CONCLUSIONS
At the 0.60-mg/kg MPH dose, more children showed substantial cognitive and behavioral gains than those who showed substantial declines in a ratio of more than 5:1. However, it may be prudent to assess cognitive change as well as behavioral effects because improvements in the former do not necessarily forecast improvements in the latter in children with attention-deficit/hyperactivity disorder and mental retardation.
Pearson
Deborah A
DA
Department of Psychiatry and Behavioral Sciences, University of Texas Medical School at Houston 77030-3497, USA. Deborah.A.Pearson@uth.tmc.edu
Lane
David M
DM
Santos
Cynthia W
CW
Casat
Charles D
CD
Jerger
Susan W
SW
Loveland
Katherine A
KA
Faria
Laura P
LP
Mansour
Rosleen
R
Henderson
Jill A
JA
Payne
Christa D
CD
Roache
John D
JD
Lachar
David
D
Cleveland
Lynne A
LA
D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000188:drug therapy*; D001519:Behavior / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D002648:Child; D003071:Cognition / Q000187:drug effects; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000150:complications*; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage / Q000494:pharmacology*
D000697:Central Nervous System Stimulants; D008774:Methylphenidate