Context: In people with intellectual disability (ID) the presentation of physical ill health can be similar to that of mental ill health. People with ID have a higher level of morbidity than the general population (Beange, McElduff & Baker, 1995) often with unrecognised, multiple and complex co-existent medical and mental health issues.
Objectives: To examine medical causes of behavioural presentations/functional decline and co-morbidities that can influence preexisting and new presentations of dementia and mental illness. Cases seen by this author will illustrate these points with particular reference to Downs Syndrome.
Key messages: The diagnosis of dementia in a person with ID should include a full clinical assessment to identify potential co-morbidities and alternative psychiatric diagnoses, the failure of which can result in increasing morbidity and possible use of unnecessary psychopharmacology.
Conclusion: Clinicians should have a high level of suspicion of undiagnosed medical problems, which may cause a decline in function in people with ID. A requirement for the diagnosis or exclusion of dementia, which can differ from the general population, is the use of appropriate assessment tools.
