title: ADHD symptom presentation and trajectory in adults with borderline and mild intellectual disability.
abstract: BACKGROUND
  This study examined symptoms and lifetime course of Attention Deficit Hyperactivity Disorder (ADHD) in adults with borderline and mild Intellectual Disability (ID).
  
  
  METHODS
  A total of 48 adults with ID and ADHD were compared with 221 adults with ADHD without ID using the informant Barkley scale for childhood and adulthood symptoms.
  
  
  RESULTS
  The ADHD/ID group presented with greater severity of (adult and childhood) symptoms compared with the non-ID group. For the ADHD/non-ID group, most symptoms improved significantly from childhood to adulthood, whereas only two symptoms changed significantly for the ID group. Principal component analysis revealed scattered loading of different items into five components for the ADHD/ID group that were not consistent with the classic clusters of inattentive, hyperactive and impulsive symptoms. A negative correlation was found between severity of symptoms and IQ.
  
  
  CONCLUSIONS
  ADHD in adults with ID may have a more severe presentation and an uneven and less favourable pattern of improvement across the lifespan in comparison with adults without ID.
authors.affiliation: South London and The Department of Maudsley Foundation Trust, Adult ADHD Service, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Xenitidis
authors.forename: Elena
authors.initials: E
authors.lastname: Paliokosta
authors.forename: E
authors.initials: E
authors.lastname: Rose
authors.forename: S
authors.initials: S
authors.lastname: Maltezos
authors.forename: J
authors.initials: J
authors.lastname: Bramham
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D002648:Child; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D007361:Intelligence Tests; D012189:Retrospective Studies; D012720:Severity of Illness Index