title: Dementia diagnostic criteria in Down syndrome.
abstract: OBJECTIVE
  Dementia is a common clinical presentation among older adults with Down syndrome. The presentation of dementia in Down syndrome differs compared with typical Alzheimer's disease. The performance of manualised dementia criteria in the International Classification of Diseases (ICD)-10 and Diagnostic and Statistical Manual of Mental Disorders-IV-Text Revision (DSM-IV-TR) is uncertain in this population.We aimed to determine the concurrent validity and reliability of clinicians' diagnoses of dementia against ICD-10 and DSM-IV-TR diagnoses. Validity of clinical diagnoses were also explored by establishing the stability of diagnoses over time.
  
  
  METHODS
  We used clinical data from memory assessments of 85 people with Down syndrome, of whom 64 (75.3%) had a diagnosis of dementia. The cases of dementia were presented to expert raters who rated the case as dementia or no dementia using ICD-10 and DSM-IV-TR criteria and their own clinical judgement.
  
  
  RESULTS
  We found that clinician's judgement corresponded best with clinically diagnosed cases of dementia, identifying 84.4% cases of clinically diagnosed dementia at the time of diagnosis. ICD-10 criteria identified 70.3% cases, and DSM-IV-TR criteria identified 56.3% cases at the time of clinically diagnosed dementia. Over time, the proportion of cases meeting ICD-10 or DSM-IV-TR diagnoses increased, suggesting that experienced clinicians used their clinical knowledge of dementia presentation in Down syndrome to diagnose the disorder at an earlier stage than would have been possible had they relied on the classic description contained in the diagnostic systems.
  
  
  CONCLUSIONS
  Clinical diagnosis of dementia in Down syndrome is valid and reliable and can be used as the standard against which new criteria such as the DSM-5 are measured.
authors.affiliation: Mental Health Sciences Unit, University College London, London, UK.|Camden Learning Disabilities Service, London, UK.
authors.forename: Rory
authors.initials: R
authors.lastname: Sheehan
authors.affiliation: Mental Health Sciences Unit, University College London, London, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Sinai
authors.affiliation: Mental Health Sciences Unit, University College London, London, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Bass
authors.affiliation: Royal Borough of Kensington and Chelsea Learning Disabilities Service, London, UK.
authors.forename: Pippa
authors.initials: P
authors.lastname: Blatchford
authors.affiliation: Central and North West London NHS Foundation Trust, Westminster Learning Disability Partnership, London, UK.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Bohnen
authors.affiliation: South London and Maudsley NHS Foundation Trust, Maudsley Hospital, London, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Bonell
authors.affiliation: Mental Health Sciences Unit, University College London, London, UK.|Haringey Learning Disabilities Partnership, London, UK.
authors.forename: Ken
authors.initials: K
authors.lastname: Courtenay
authors.affiliation: Mental Health Sciences Unit, University College London, London, UK.|Camden Learning Disabilities Service, London, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Hassiotis
authors.affiliation: Hertfordshire Partnership University NHS Foundation Trust, Lister Hospital, Stevenage, UK.
authors.forename: Therese
authors.initials: T
authors.lastname: Markar
authors.affiliation: Department of Forensic and Neurodevelopmental Sciences (FANS), Institute ofPsychiatry, London, UK.
authors.forename: Jane
authors.initials: J
authors.lastname: McCarthy
authors.affiliation: Hertfordshire Partnership University NHS Foundation Trust, Lister Hospital, Stevenage, UK.
authors.forename: Kamalika
authors.initials: K
authors.lastname: Mukherji
authors.affiliation: Sutton and Merton Mental Health Learning Disability Team, Jubilee Health Centre East, Surrey, UK.
authors.forename: Asim
authors.initials: A
authors.lastname: Naeem
authors.affiliation: Islington Learning Disabilities Partnership, London, UK.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Paschos
authors.affiliation: Royal Borough of Kensington and Chelsea Learning Disabilities Service, London, UK.
authors.forename: Natalia
authors.initials: N
authors.lastname: Perez-Achiaga
authors.affiliation: Hertfordshire Partnership University NHS Foundation Trust, Community Support Unit, Watford, UK.
authors.forename: Vijaya
authors.initials: V
authors.lastname: Sharma
authors.affiliation: Hackney Learning Disabilities Team, Hackney Service Centre, London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Thomas
authors.affiliation: Mental Health Sciences Unit, University College London, London, UK.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Walker
authors.affiliation: Mental Health Sciences Unit, University College London, London, UK.|Islington Learning Disabilities Partnership, London, UK.
authors.forename: Andre
authors.initials: A
authors.lastname: Strydom
mesh_terms: D000328:Adult; D000368:Aged; D003704:Dementia / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004314:Down Syndrome / Q000150:complications*; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results
keywords: DSM-IV-TR; Down syndrome; ICD-10; clinical judgement; dementia; diagnosis