title: Abnormal functional connectivity in children with attention-deficit/hyperactivity disorder.
abstract: BACKGROUND
  Attention-deficit/hyperactivity disorder (ADHD) is typically characterized by symptoms of inattention and hyperactivity/impulsivity, but there is increased recognition of a motivation deficit too. This neuropathology may reflect dysfunction of both attention and reward-motivation networks.
  
  
  METHODS
  To test this hypothesis, we compared the functional connectivity density between 247 ADHD and 304 typically developing control children from a public magnetic resonance imaging database. We quantified short- and long-range functional connectivity density in the brain using an ultrafast data-driven approach.
  
  
  RESULTS
  Children with ADHD had lower connectivity (short- and long-range) in regions of the dorsal attention (superior parietal cortex) and default-mode (precuneus) networks and in cerebellum and higher connectivity (short-range) in reward-motivation regions (ventral striatum and orbitofrontal cortex) than control subjects. In ADHD children, the orbitofrontal cortex (region involved in salience attribution) had higher connectivity with reward-motivation regions (striatum and anterior cingulate) and lower connectivity with superior parietal cortex (region involved in attention processing).
  
  
  CONCLUSIONS
  The enhanced connectivity within reward-motivation regions and their decreased connectivity with regions from the default-mode and dorsal attention networks suggest impaired interactions between control and reward pathways in ADHD that might underlie attention and motivation deficits in ADHD.
authors.affiliation: National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA. tomasi@bnl.gov
authors.forename: Dardo
authors.initials: D
authors.lastname: Tomasi
authors.forename: Nora D
authors.initials: ND
authors.lastname: Volkow
mesh_terms: D001288:Attention / Q000502:physiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology* / Q000523:psychology; D001931:Brain Mapping / Q000379:methods / Q000523:psychology; D002531:Cerebellum / Q000503:physiopathology*; D002648:Child; D003342:Corpus Striatum / Q000503:physiopathology*; D016208:Databases, Factual; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000523:psychology; D008297:Male; D009042:Motivation / Q000502:physiology; D009434:Neural Pathways / Q000503:physiopathology; D010296:Parietal Lobe / Q000503:physiopathology*; D012201:Reward