title: Fatigue in an adult attention deficit hyperactivity disorder population: A trans-diagnostic approach.
abstract: OBJECTIVE
  Trans-diagnostic approaches suggest that key cognitive and behavioural processes maintain symptoms across a wide range of mental health disorders. Fatigue is a common clinical feature of attention deficit hyperactivity disorder (ADHD) in adulthood; however, empirical data supporting its prevalence are lacking. This study aimed to collate outcomes from outpatient services to (1) investigate the prevalence of fatigue in adults with ADHD, (2) examine symptoms of ADHD in adults with chronic fatigue syndrome (CFS), and (3) consider secondary clinical characteristics common to both disorder groups.
  
  
  METHODS
  Measures of self-reported fatigue were compared across groups of adults with ADHD (N = 243), CFS (N = 86), and healthy controls (HC) (N = 211) using a between-subjects cross-sectional design. Groups were also compared on secondary clinical measures of functional impairment, mood, anxiety, sleep, self-efficacy, and their beliefs about the acceptability of expressing emotions.
  
  
  RESULTS
  The ADHD group were significantly more fatigued than HC with 62% meeting criteria for fatigue caseness. ADHD symptoms were significantly greater in the CFS group than in HC. ADHD and CFS groups did not differ significantly on measures of functional impairment, mood, and self-efficacy. No significant differences were detected on measures of anxiety when items relating to physical restlessness were removed from the analysis.
  
  
  CONCLUSIONS
  Adults with ADHD experience greater fatigue than HC. Adults with CFS and ADHD share many trans-diagnostic clinical characteristics, including difficulties with low mood, anxiety, and reduced self-efficacy, which impact upon their overall functioning. Further research is required to investigate extraneous factors mediating fatigue severity in these clinical groups.
  
  
  CONCLUSIONS
  Fatigue is a common clinical feature of attention deficit hyperactivity disorder (ADHD) in adulthood. Evidence-based interventions for chronic fatigue syndrome could be adapted to address fatigue in ADHD in adults.
authors.affiliation: King's College London, King's Health Partners, (formerly Behavioural and Developmental Psychiatry Clinical Academic Group, Maudsley Adult ADHD Service, South London and Maudsley NHS Foundation Trust), London, UK.
authors.forename: Denise C
authors.initials: DC
authors.lastname: Rogers
authors.affiliation: King's College London, King's Health Partners, Psychological Medicine Clinical Academic Group, Chronic Fatigue Research and Treatment Unit (formerly Behavioural and Developmental Psychiatry Clinical Academic Group, Maudsley Adult ADHD Service), South London and Maudsley NHS Foundation Trust, London, UK.
authors.forename: Antonia J
authors.initials: AJ
authors.lastname: Dittner
authors.affiliation: Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, UK.
authors.forename: Katharine A
authors.initials: KA
authors.lastname: Rimes
authors.affiliation: Department of Psychological Medicine, King's College London, Weston Education Centre, London, UK.
authors.forename: Trudie
authors.identifier: http://orcid.org/0000-0003-0775-1045
authors.initials: T
authors.lastname: Chalder
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000453:epidemiology*; D015673:Fatigue Syndrome, Chronic / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D057566:Self Report; D055815:Young Adult
keywords: attention deficit hyperactivity disorder; chronic fatigue; trans-diagnostic