Treatment effects of methylphenidate on cognitive functioning in children with mental retardation and ADHD.
OBJECTIVE
Cognitive effects of stimulant medication were investigated in children with mental retardation (MR) and attention-deficit/hyperactivity disorder (ADHD).


METHODS
Performance on tasks tapping sustained attention, visual and auditory selective attention, inhibition, and immediate memory was assessed for 24 children (mean age 10.9 years) during a placebo-controlled, double-blind, crossover treatment trial with 0.15, 0.30, and 0.60 mg/kg b.i.d. dosages of methylphenidate (MPH).


RESULTS
Successively higher MPH doses were associated with consistent gains in cognitive task performance, with optimal performance noted at the highest dose. Analysis of dose-response curves revealed significant linear components of trend on measures tapping sustained attention, visual selective attention, auditory selective attention, as well as two tasks tapping inhibition/impulsivity: delay of gratification and match-to-sample. No evidence of a curvilinear dose-response relationship emerged for any measure.


CONCLUSIONS
Inattention and disinhibition/impulsivity decline with MPH treatment in children with ADHD/MR, and consistent with the Multimodal Treatment Study of ADHD, higher MPH doses are most effective. These findings also suggest that cognitive testing, together with behavioral and medical assessment, can be an effective tool in assessing stimulant response in children with ADHD/MR.
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
Santos
Cynthia W
CW
Casat
Charles D
CD
Lane
David M
DM
Jerger
Susan W
SW
Roache
John D
JD
Loveland
Katherine A
KA
Lachar
David
D
Faria
Laura P
LP
Payne
Christa D
CD
Cleveland
Lynne A
LA
D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000188:drug therapy*; 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; D008570:Memory, Short-Term / Q000187:drug effects; D008774:Methylphenidate / Q000008:administration & dosage / Q000494:pharmacology*
D000697:Central Nervous System Stimulants; D008774:Methylphenidate