title: Brain biochemical effects of methylphenidate treatment using proton magnetic spectroscopy in youth with attention-deficit hyperactivity disorder: a controlled pilot study.
abstract: BACKGROUND
  This study conducted spectroscopic analyses using proton (1H) Magnetic Resonance Spectroscopy (at 4 Tesla) in a sample of adolescents with Attention Deficit Hyperactivity Disorder (ADHD), before and after treatment with extended release methylphenidate (OROS MPH), as compared to a sample of healthy comparators.
  
  
  OBJECTIVE
  The main aim of this study is to use 1H MRS to measure differences in brain biochemistry between adolescents with and without ADHD, and to assess changes in cerebral biochemistry, before and after stimulant treatment in ADHD youth.
  
  
  RESULTS
  Subjects with ADHD were medically healthy adolescents treated in an open label fashion with OROS MPH (mean dose: 54 mg/day; 0.90 mg/kg/day). Subjects with ADHD were scanned before and after OROS MPH treatment. Healthy comparators were scanned once. Magnetic resonance (MR) spectroscopy studies were performed on a 4.0 T Varian Unity/Inova MR scanner; proton spectra were acquired from the Anterior Cingulate Cortex (ACC). Data were analyzed using MANOVA and repeated measurement ANOVA. Higher metabolite ratios (Glutamate/myo-inositol, Glutamine/myo-inositol, Glutamate + Glutamine/myo-inositol) were observed in the ACC in untreated ADHD subjects as compared to controls, and to treated ADHD youth; these group differences did not reach the a priori threshold for statistical significance.
  
  
  CONCLUSIONS
  These preliminary findings suggest the presence of glutamatergic abnormalities in adolescents with ADHD, which may normalize with MPH treatment. Larger sample, controlled studies are needed to confirm these preliminary findings.
authors.affiliation: Clinical and Research Program in Pediatric Psychopharmacology, Massachusetts General Hospital, Boston, 02138, USA. phammerness@partners.org
authors.forename: Paul
authors.initials: P
authors.lastname: Hammerness
authors.forename: Joseph
authors.initials: J
authors.lastname: Biederman
authors.forename: Carter
authors.initials: C
authors.lastname: Petty
authors.forename: Aude
authors.initials: A
authors.lastname: Henin
authors.forename: Constance M
authors.initials: CM
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism; D016022:Case-Control Studies; D000697:Central Nervous System Stimulants / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology / Q000627:therapeutic use*; D010865:Pilot Projects; D011522:Protons; D011569:Psychiatric Status Rating Scales; D011877:Radionuclide Imaging
chemical_list: D000697:Central Nervous System Stimulants; D011522:Protons; D005973:Glutamine; D008774:Methylphenidate; D018698:Glutamic Acid