title: Effects of methylphenidate discontinuation on cerebral blood flow in prepubescent boys with attention deficit hyperactivity disorder.
abstract: Methylphenidate (MPH) is an effective symptomatic treatment of attention deficit hyperactivity disorder (ADHD), but the mechanisms of its therapeutic action have not been fully elucidated. To address this issue, we assessed the effects of discontinuation of chronic MPH treatment on regional cerebral blood flow (rCBF) in ADHD patients.
  
  
  METHODS
  Twenty-two prepubescent boys with ADHD (age range, 8.2-11.5 y) and 7 healthy volunteers were studied with SPECT on and off MPH. Their rCBF data were automatically normalized to whole-brain counts and coregistered with standard anatomic space. rCBF changes were evaluated with statistical parametric mapping based on voxel-by-voxel ANOVA.
  
  
  RESULTS
  When the subjects were not taking MPH, rCBF was higher in the motor, premotor, and the anterior cingulate cortices (Brodmann's areas 4, 6, and 32).
  
  
  CONCLUSIONS
  Brief discontinuation of MPH treatment is associated with increased motor and anterior cingulate cortical activity. Our findings suggest that MPH treatment modulates motor and anterior cingulate cortical activity directly or indirectly. Alternatively, our findings may be related to MPH withdrawal. These data provide novel information on the potential mechanisms of the therapeutic action of MPH. Furthermore, they are clinically relevant to the commonly occurring brief interruptions in MPH treatment.
authors.affiliation: Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA. langlebe@mail.med.upenn.edu
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Langleben
authors.forename: Paul D
authors.initials: PD
authors.lastname: Acton
authors.forename: Glenn
authors.initials: G
authors.lastname: Austin
authors.forename: Igor
authors.initials: I
authors.lastname: Elman
authors.forename: Gary
authors.initials: G
authors.lastname: Krikorian
authors.forename: John R
authors.initials: JR
authors.lastname: Monterosso
authors.forename: Orith
authors.initials: O
authors.lastname: Portnoy
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Ridlehuber
authors.forename: H William
authors.initials: HW
authors.lastname: Strauss
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D001921:Brain / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D002648:Child; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D008774:Methylphenidate