Lisa Stanton is a specialist registrar in old age psychiatry and general adult psychiatry in Nottingham (Nottinghamshire Healthcare NHS Trust, Duncan Macmillan House, Porchester Road, Nottingham NG6 3AA, UK. E-mail: Liza.Stanton{at}nottshc.nhs.uk). Her research interests are in liaison in old age psychiatry, the interface between old age psychiatry and learning disability services, and neuropsychiatry. Rikus Coetzee is also a specialist registrar in general adult psychiatry and old age psychiatry at Duncan Macmillan House, Nottingham. His research interests are in the treatment and epidemiology of trauma-related neurosis in the elderly and the use of cognitivebehavioural therapy with elderly people.
Downs syndrome is the most common genetic disorder seen in clinical practice: about 94% occurs because of non-disjunction of chromosome 21 and 35% because of translocation. Individuals increasingly survive to middle and old age, probably because of advances in medical treatment and improved living conditions. People with Downs syndrome have an increased risk of developing Alzheimers disease in middle age. Within ICD10 and DSMIV classifications there is no consensus on the diagnosis of dementia in people with learning disability. New treatments have been licensed for use in mild to moderate Alzheimers disease (e.g. acetylcholinesterase inhibitors and memantine). The comorbid picture of Downs syndrome and Alzheimers disease presents a unique challenge to the clinician in both diagnosis and management.