(1)H-Magnetic resonance spectroscopy study of stimulant medication effect on brain metabolites in French Canadian children with attention deficit hyperactivity disorder.
BACKGROUND
Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in school aged children. Functional abnormalities have been reported in brain imaging studies in ADHD populations. Psychostimulants are considered as the first line treatment for ADHD. However, little is known of the effect of stimulants on brain metabolites in ADHD patients.


OBJECTIVE
To compare the brain metabolite concentrations in children with ADHD and on stimulants with those of drug naïve children with ADHD, versus typically developed children, in a homogenous genetic sample of French Canadians.


METHODS
Children with ADHD on stimulants (n=57) and drug naïve children with ADHD (n=45) were recruited, as well as typically developed children (n=38). The presence or absence of ADHD diagnosis (Diagnostic and Statistical Manual of Mental Disorders IV criteria) was based on clinical evaluation and The Diagnostic Interview Schedule for Children IV. All children (n=140) underwent a proton magnetic resonance spectroscopy session to measure the ratio of N-acetyl-aspartate, choline, glutamate, and glutamate-glutamine to creatine, respectively, in the left and right prefrontal and striatal regions of the brain, as well as in the left cerebellum.


RESULTS
When compared with drug naïve children with ADHD, children with ADHD on stimulants and children typically developed were found to have higher choline ratios in the left prefrontal region (P=0.04) and lower N-acetyl-aspartate ratios in the left striatum region (P=0.01), as well as lower glutamate-glutamine ratios in the left cerebellum (P=0.05). In these three regions, there was no difference between children with ADHD on stimulants and typically developed children.


CONCLUSIONS
Therapeutic psychostimulant effects in children with ADHD may be mediated by normalization of brain metabolite levels, particularly in the left fronto-striato-cerebellar regions.
Department of Psychiatry Sainte-Justine Hospital, Montreal, Quebec, Canada ; Department of Psychiatry, University of Montreal, Montreal, Quebec, Canada.
Leila
L
Benamor
attention deficit; brain; hyperactivity; spectroscopy; stimulants