title: Functional magnetic resonance imaging study on the effects of acute single administration of paroxetine on motivation-related brain activity.
abstract: OBJECTIVE
  The aim of the present study was to investigate the effects of acute paroxetine administration on brain activity related to motivation.
  
  
  METHODS
  Sixteen healthy subjects participated in a randomized, single-blind, no-drug/placebo-controlled, cross-over study. After administration of no drug, placebo or paroxetine (selective serotonin reuptake inhibitor; 20 mg), subjects underwent functional magnetic resonance imaging while performing a monetary incentive delay task. We analyzed the differences in brain activities of the reward anticipation/motor preparation period that are subject to motivational modulation. For this purpose, we subdivided the incentive trials on the basis of whether the reaction times (RT) were slower or faster than the subject's mean RT (slow RT and fast RT trials).
  
  
  RESULTS
  No drug and placebo showed robust activation differences in the globus pallidus and putamen for the fast RT trials compared to the slow RT trials, whereas paroxetine showed none. Paroxetine showed significantly lower activations in the globus pallidus, insula, putamen and dorsolateral prefrontal cortex compared to no drug in the fast RT trials.
  
  
  CONCLUSIONS
  Paroxetine single acute administration diminished brain activity induced by motivation in healthy subjects. This may partially explain the increased lack of motivation seen in patients with relatively mild symptoms after taking a dose of paroxetine for the first time.
authors.affiliation: Tamagawa University Brain Science Institute, Tokyo, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Marutani
authors.forename: Noriaki
authors.initials: N
authors.lastname: Yahata
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Takehito
authors.initials: T
authors.lastname: Ito
authors.forename: Manami
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Masato
authors.initials: M
authors.lastname: Matsuura
authors.forename: Eisuke
authors.initials: E
authors.lastname: Matsushima
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okubo
authors.forename: Hidenori
authors.initials: H
authors.lastname: Suzuki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000328:Adult; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009042:Motivation / Q000502:physiology*; D017374:Paroxetine / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology
chemical_list: D017374:Paroxetine