The prevalence rate of dementia in older adults with intellectual disability (ID) is comparable with that of the general population and is significantly higher in people with Down Syndrome (DS). It is recommended that diagnosis should be made following history, physical and mental state examination, cognitive assessment, blood tests and, ideally, neuroimaging. However, experience suggests that dementia may be underdiagnosed in this patient group thereby restricting access to appropriate management.

We aimed to elucidate the barriers to a timely diagnosis of dementia in the ID population attending a specialised ID memory clinic in London, UK.

We conducted a service review of the Clinic, retrospectively reviewing the records of all patients seen in 2011 to assess attendance and diagnosis rate, co-morbid physical and mental illness and the completion of neuroimaging and blood tests.

32 patients were seen at least once during 2011 in the memory clinic, of whom 11 (34%) received a diagnosis of dementia. 22 (69%) of those seen had DS and 18 (56%) were male. 12 (38%) patients have thyroid dysfunction and 8 (25%) have epilepsy. 23 patients had completed a DLD in the past year and 14 (44%) had completed more than one DLD. 12 (38%) patients had a previous brain scan and 27 (84%) patients had had blood tests in the previous year.

Comorbid physical illnesses, consistent attendance at appointments, access to psychological assessment and willingness to undergo neuroimaging and phlebotomy are significant barriers to diagnosis of dementia in patients with ID.