Striatal creatine and glutamate/glutamine in attention-deficit/hyperactivity disorder.
OBJECTIVE
The glutamatergic prefrontal-striatal pathway has been implicated previously in the neurobiology of attention-deficit/hyperactivity disorder (ADHD). We used short echo proton magnetic resonance spectroscopy (1H-MRS) to examine glutamate in the prefrontal cortex, left striatum, and, as a control area, the occipital lobe.


METHODS
Thirteen treatment-naïve ADHD children and 10 healthy comparison subjects participated. All were males between the ages of 6 to 11 years of age. Twelve ADHD subjects were scanned after 8 weeks of treatment.


RESULTS
Striatal glutamate, glutamate/glutamine (Glx) and creatine concentrations were greater in the ADHD subjects at baseline as compared to controls. Only striatal creatine, not glutamate or Glx, was reduced after stimulant treatment in the ADHD patients. No significant differences between groups were noted in the remainder of the striatal metabolites or any of the occipital lobe or prefrontal cortex metabolites.


CONCLUSIONS
These findings provide initial evidence of a striatal creatine/glutamatergic dysregulation in ADHD.
Carrey
Normand J
NJ
Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada. Normand.Carrey@iwk.nshealth.ca
MacMaster
Frank P
FP
Gaudet
Laura
L
Schmidt
Matthias H
MH
D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000503:physiopathology*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use; D002648:Child; D002794:Choline / Q000378:metabolism; D003342:Corpus Striatum / Q000187:drug effects / Q000503:physiopathology*; D003401:Creatine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D007294:Inositol / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use; D009434:Neural Pathways / Q000187:drug effects / Q000503:physiopathology; D009778:Occipital Lobe / Q000187:drug effects / Q000503:physiopathology; D010725:Phosphocreatine / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects / Q000503:physiopathology*; D012016:Reference Values
D000697:Central Nervous System Stimulants; D010725:Phosphocreatine; D005973:Glutamine; D008774:Methylphenidate; D018698:Glutamic Acid; D007294:Inositol; D003401:Creatine; D002794:Choline