Functional effects of the DAT1 polymorphism on EEG measures in ADHD.
OBJECTIVE
This paper examines whether dopamine transporter gene (DAT1) allele status mediates medication-related change in cognitive and neurophysiological measures among children with attention-deficiency/hyperactivity disorder (ADHD).


METHODS
A single 10-mg dose of methylphenidate was given in a double-blind, placebo-controlled fashion to children with ADHD who were seen for cognitive testing and EEG recording. Buccal samples were obtained and genotyped for the DAT1 polymorphism.


RESULTS
DAT1 allele status was associated with performance on a sustained attention task and medication-related EEG changes. Compared with those with one or more copies of the DAT1 9-repeat allele (9R), children with two copies of the 10-repeat allele (10R) exhibited poorer performance on the vigilance task. In addition, children with 10R exhibited medication-related EEG changes of increased central and parietal beta power, decreased right frontal theta power, and lower theta/beta ratios; 9R carriers showed the opposite pattern.


CONCLUSIONS
The data suggest that the DAT1 polymorphism mediates medication-related changes in cortical activity among children with ADHD.
Loo
Sandra K
SK
Department of Psychiatry and Biobehavioral Sciences, UCLA-NPI, Los Angeles, USA. SLoo@mednet.ucla.edu
Specter
Elaine
E
Smolen
Andrew
A
Hopfer
Christian
C
Teale
Peter D
PD
Reite
Martin L
ML
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000235:genetics*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis; D050483:Dopamine Plasma Membrane Transport Proteins; D004311:Double-Blind Method; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000235:genetics*; D008774:Methylphenidate / Q000627:therapeutic use; D009419:Nerve Tissue Proteins; D009483:Neuropsychological Tests; D011110:Polymorphism, Genetic / Q000235:genetics*
D000697:Central Nervous System Stimulants; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human; D008774:Methylphenidate