Methylphenidate treatment in children with borderline IQ and mental retardation: analysis of three aggregated studies.
OBJECTIVE
To determine response of low-IQ children with attention deficit hyperactivity disorder (ADHD) symptoms to methylphenidate (MPH).


METHODS
An aggregated analysis was conducted in 90 children with low IQ who received the same dose regimen of MPH in three independent, placebo-controlled studies. Active drug and placebo were given from 2 to 4 weeks each. Outcome measures included teacher and parent ratings on standardized behavior scales (mean n = 84), performance on computer-controlled cognitive-motor tests (n = 62), and measures of cardiovascular response (n = 85).


RESULTS
Both teachers and parents rated the children consistently as being improved on subscales assessing attention, overactivity, and conduct problems. Some 44% of the subjects showed at least a 30% reduction compared with placebo on teacher ratings. MPH improved accuracy on several cognitive tests, response speed was increased on some, and seat activity declined for one of three tests; heart rate was mildly increased (3.9 beats/minute) with MPH. Analyses of IQ and mental age as moderator variables suggested that lower functional level (especially lower IQ) may be associated with a less favorable response to MPH.


CONCLUSIONS
Children with low IQ and ADHD clearly respond to MPH, but their rate of beneficial response appears to be well under that of normal-IQ children and more varied. Different attentional mechanisms may moderate response to psychostimulants.
Aman
Michael G
MG
Department of Psychiatry, School of Medicine, University of Auckland, Auckland, New Zealand. aman1@osu.edu
Buican
Brett
B
Arnold
L Eugene
LE
D000293:Adolescent; D000294:Adolescent Behavior; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D002652:Child Behavior; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000150:complications / Q000188:drug therapy*; D007361:Intelligence Tests; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance; D016896:Treatment Outcome
D000697:Central Nervous System Stimulants; D008774:Methylphenidate