title: Abnormal striatal BOLD responses to reward anticipation and reward delivery in ADHD.
abstract: Altered reward processing has been proposed to contribute to the symptoms of attention deficit hyperactivity disorder (ADHD). The neurobiological mechanism underlying this alteration remains unclear. We hypothesize that the transfer of dopamine release from reward to reward-predicting cues, as normally observed in animal studies, may be deficient in ADHD. Functional magnetic resonance imaging (fMRI) was used to investigate striatal responses to reward-predicting cues and reward delivery in a classical conditioning paradigm. Data from 14 high-functioning and stimulant-naïve young adults with elevated lifetime symptoms of ADHD (8 males, 6 females) and 15 well-matched controls (8 males, 7 females) were included in the analyses. During reward anticipation, increased blood-oxygen-level-dependent (BOLD) responses in the right ventral and left dorsal striatum were observed in controls, but not in the ADHD group. The opposite pattern was observed in response to reward delivery; the ADHD group demonstrated significantly greater BOLD responses in the ventral striatum bilaterally and the left dorsal striatum relative to controls. In the ADHD group, the number of current hyperactivity/impulsivity symptoms was inversely related to ventral striatal responses during reward anticipation and positively associated with responses to reward. The BOLD response patterns observed in the striatum are consistent with impaired predictive dopamine signaling in ADHD, which may explain altered reward-contingent behaviors and symptoms of ADHD.
authors.affiliation: Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Furukawa
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil ; Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bado
authors.affiliation: Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa, Japan.
authors.forename: Gail
authors.initials: G
authors.lastname: Tripp
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil ; Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Mattos
authors.affiliation: Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa, Japan.
authors.forename: Jeff R
authors.initials: JR
authors.lastname: Wickens
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil ; Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Ivanei E
authors.initials: IE
authors.lastname: Bramati
authors.affiliation: University of Otago, Dunedin, New Zealand.
authors.forename: Brent
authors.initials: B
authors.lastname: Alsop
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Fernanda Meireles
authors.initials: FM
authors.lastname: Ferreira
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Debora
authors.initials: D
authors.lastname: Lima
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil ; Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Tovar-Moll
authors.affiliation: VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Sergeant
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Jorge
authors.initials: J
authors.lastname: Moll
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D016022:Case-Control Studies; D003342:Corpus Striatum / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012201:Reward; D055815:Young Adult