title: The acute effect of methylphenidate on cerebral blood flow in boys with attention-deficit/hyperactivity disorder.
abstract: Methylphenidate (MPH) is the most commonly prescribed treatment for attention-deficit/hyperactivity disorder (ADHD). The therapeutic mechanisms of MPH are not, however, fully understood. We studied the effects of MPH on brain activity in male children and adolescents with ADHD, using the blood flow radiotracer technetium-99m ethyl cysteinate dimer ((99m)Tc-ECD) and single-photon emission tomography (SPET). The study was randomized, double blind, and placebo controlled (MPH group, n=19; placebo group, n=17), Radiotracer was administered during the performance of the Continuous Performance Test and before and after 4 days of MPH treatment. Statistical parametric mapping (SPM99) analysis showed a significant reduction in regional cerebral blood flow in the left parietal region in the MPH group compared with the placebo group (P<0.05, corrected for multiple comparisons). Our findings suggest that the posterior attentional system, which includes the parietal cortex, may have a role in the mediation of the therapeutic effects of MPH in ADHD.
authors.affiliation: Department of Psychiatry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Szobot
authors.forename: Carla
authors.initials: C
authors.lastname: Ketzer
authors.forename: Renato D
authors.initials: RD
authors.lastname: Cunha
authors.forename: Maria A
authors.initials: MA
authors.lastname: Parente
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Langleben
authors.forename: Paul D
authors.initials: PD
authors.lastname: Acton
authors.forename: Flávio
authors.initials: F
authors.lastname: Kapczinski
authors.forename: Luis A P
authors.initials: LA
authors.lastname: Rohde
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D002648:Child; D003545:Cysteine / Q000031:analogs & derivatives*; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage*; D015609:Organotechnetium Compounds; D010296:Parietal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D010919:Placebos; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals
chemical_list: D015609:Organotechnetium Compounds; D010919:Placebos; D019275:Radiopharmaceuticals; D008774:Methylphenidate; C059659:technetium Tc 99m bicisate; D003545:Cysteine