title: Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in adult psychiatry. A 20-year register study.
abstract: OBJECTIVE
  Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are increasingly recognized in adults. This study aimed to assess trends in diagnostic practice, diagnostic delay and comorbidity regarding ADHD and ASD in adult psychiatric patients.
  
  
  METHODS
  Individuals with diagnosed ADHD or ASD were identified in an adult psychiatry register comprising 56,462 patients.
  
  
  RESULTS
  ADHD was diagnosed in up to 2.7% and ASD in 1.3% of the patients. Most cases were diagnosed within 2 years of first contact with adult psychiatry, but some patients were treated for 10 years or more before being diagnosed with ADHD or ASD. Seventy per cent of ADHD and 56% of ASD patients were treated as outpatients only. Other psychiatric diagnoses were registered in about 60%. Affective disorders were common in patients with ADHD. Psychoses and intellectual disability were more common in ASD patients. Psychoactive substance use-related disorders were considerably more common in those with ADHD. Concomitant ADHD and ASD were seldom diagnosed in this clinical material.
  
  
  CONCLUSIONS
  ADHD and ASD were probably much underdiagnosed in the studied group of psychiatric patients. Other psychiatric diagnoses were common, but not ADHD with concomitant ASD.
authors.affiliation: Department of Clinical Sciences/Psychiatry, Lund University, and Gillberg Neuropsychiatry Centre, University of Gothenburg , Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Nylander
authors.forename: Maria
authors.initials: M
authors.lastname: Holmqvist
authors.forename: Lars
authors.initials: L
authors.lastname: Gustafson
authors.forename: Christopher
authors.initials: C
authors.lastname: Gillberg
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000453:epidemiology*; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis* / Q000453:epidemiology*; D015897:Comorbidity; D057210:Delayed Diagnosis; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology; D015995:Prevalence; D012042:Registries; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult