title: Does attention-deficit-hyperactivity disorder exacerbate executive dysfunction in children with neurofibromatosis type 1?
abstract: OBJECTIVE
  Although approximately 40% of children with neurofibromatosis type 1 (NF1) meet diagnostic criteria for attention-deficit-hyperactivity disorder (ADHD), the impact of ADHD on the executive functioning of children with NF1 is not understood. We investigated whether spatial working memory and response inhibition are impaired in children with NF1 without a diagnosis of ADHD and whether executive deficits are exacerbated in children with a comorbid diagnosis.
  
  
  METHODS
  Forty-nine children aged 7 to 15 years with NF1 only (31 males, 18 females; mean age 11y, SD 2y 4mo) or 35 with NF1 and ADHD (18 males, 17 females; mean age 10y 8mo, SD 2y 4mo) and 30 typically developing comparison children (16 males, 14 females; mean age 10y, SD 2y 8mo) were compared on measures of spatial working memory and response inhibition. Group differences in IQ and visuospatial ability were controlled for as required.
  
  
  RESULTS
  Compared with typically developing children, children with NF1 with or without comorbid ADHD demonstrated significant impairment of both spatial working memory (both p<0.004) and inhibitory control (both p<0.010). There were, however, no differences between the two NF1 groups in spatial working memory (p=0.91) or response inhibition (p=0.78).
  
  
  CONCLUSIONS
  Executive dysfunction occurs with the same severity in children with NF1, whether or not they have a comorbid diagnosis of ADHD, suggesting that executive impairments are not unique contributors to ADHD symptomatology in NF1. The findings are discussed within the context of recent evidence in Nf1 optic glioma (OPG) mice, in which a mechanistic connection between NF1 gene expression, executive system failure, and dopaminergic pathway integrity has been established.
authors: Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors: Jonathan M
authors: JM
authors: Payne
authors: Shelley S
authors: SS
authors: Arnold
authors: Natalie A
authors: NA
authors: Pride
authors: Kathryn N
authors: KN
authors: North
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000523:psychology; D002648:Child; D015897:Comorbidity; D056344:Executive Function; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008570:Memory, Short-Term; D009456:Neurofibromatosis 1 / Q000175:diagnosis / Q000523:psychology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D009949:Orientation; D010364:Pattern Recognition, Visual; D011340:Problem Solving; D011446:Prospective Studies; D011594:Psychometrics; D011597:Psychomotor Performance; D013028:Space Perception; D014888:Wechsler Scales