title: Cognitive dysfunction in adolescents with chronic fatigue: a cross-sectional study.
abstract: OBJECTIVE
  To compare cognitive function in adolescents with chronic fatigue with cognitive function in healthy controls (HC).
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Paediatric department at Oslo University Hospital, Norway.
  
  
  METHODS
  120 adolescents with chronic fatigue (average age 15.4 years; range 12-18) and 39 HC (average age 15.2 years; range 12-18).
  
  
  METHODS
  The adolescents completed a neurocognitive test battery measuring processing speed, working memory, cognitive inhibition, cognitive flexibility, verbal learning and verbal memory, and questionnaires addressing demographic data, depression symptoms, anxiety traits, fatigue and sleep problems. Parents completed the Behaviour Rating Inventory of Executive Function (BRIEF), which measures the everyday executive functions of children.
  
  
  RESULTS
  Adolescents with chronic fatigue had impaired cognitive function compared to HC regarding processing speed (mean difference 3.3, 95% CI 1.1 to 5.5, p=0.003), working memory (-2.4, -3.7 to -1.1, p<0.001), cognitive inhibition response time (6.2, 0.8 to 11.7, p=0.025) and verbal learning (-1.7, -3.2 to -0.3, p=0.022). The BRIEF results indicated that everyday executive functions were significantly worse in the chronic fatigue group compared to the HC (11.2, 8.2 to 14.3, p<0.001). Group differences remained largely unaffected when adjusted for symptoms of depression, anxiety traits and sleep problems.
  
  
  CONCLUSIONS
  Adolescents with chronic fatigue had impaired cognitive function of clinical relevance, measured by objective cognitive tests, in comparison to HC. Working memory and processing speed may represent core difficulties.
authors: Department of Paediatrics, Oslo University Hospital, Oslo, Norway Department of Paediatrics, Innlandet Hospital Trust, Lillehammer, Norway.
authors: Dag
authors: D
authors: Sulheim
authors: Medical Faculty, Institute of Clinical Medicine, University of Oslo, Oslo, Norway Department of Anesthesiology and Critical Care, Oslo University Hospital, Oslo, Norway.
authors: Even
authors: E
authors: Fagermoen
authors: Medical Faculty, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors: Øyvind Stople
authors: ØS
authors: Sivertsen
authors: Medical Faculty, Institute of Nursing Sciences, Oslo and Akershus University College of Applied Sciences, Norway and Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Anette
authors: A
authors: Winger
authors: Department of Paediatrics, Oslo University Hospital, Oslo, Norway Division of Medicine and Laboratory Sciences, Medical Faculty, University of Oslo, Oslo, Norway Department of Paediatrics, Akershus University Hospital, Nordbyhagen, Norway.
authors: Vegard Bruun
authors: VB
authors: Wyller
authors: Innlandet Hospital Trust, Lillehammer, Norway Institute of Psychology, University of Oslo, Oslo, Norway.
authors: Merete Glenne
authors: MG
authors: Øie
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002908:Chronic Disease; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000523:psychology*; D015673:Fatigue Syndrome, Chronic / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests
keywords: Adolescent Health; Chronic Fatigue Syndrome