Treatment for Alzheimer's disease in people with learning disabilities: NICE guidance

In January 2001 the National Institute for Clinical Excellence (NICE) published Guidance on the Use of Donepezil, Rivastigmine and Galantamine for the Treatment of Alzheimer's Disease. The guidance indicates that the drugs should be made available within the National Health Service to people with mild to moderate Alzheimer's disease whose minimental state examination (MMSE) score is above 12 points. The Institute's guidance does not mention the use of anti-dementia drugs in people with learning disabilities and Alzheimer's disease. Studies have shown that the prevalence of Alzheimer's disease in those with learning disabilities is higher than in the normal population (Patel et al, 1993). This is likely to increase in the future because of the rising life expectancy of people with learning disabilities (Zigman et al, 1997). In Down's syndrome, approximately 40% develop dementia of Alzheimer type by the age of 60 (Holland et al, 1998).

It is known that clinical evidence for the effectiveness of various psychiatric treatments in the learning disability population is scanty and specialists rely on evidence from the normal population. In this situation, a specialist in the psychiatry of learning disability might consider following the NICE guidance in treating dementia in the people under his or her care. However, there is a major problem, as NICE guidance suggests that treatment should be monitored by MMSE score but the MMSE cannot be used reliably in people with learning disabilities (Deb & Braganza, 1999). This means that NICE guidance on the use of antidementia drugs is not applicable to people with learning disabilities. This is likely to discourage specialists from prescribing treatment for some patients with a learning disability and Alzheimer's disease who may benefit from it in future. In its guidance, NICE mentioned limitations on the use of the MMSE in people whose Alzheimer's disease is complicated by dysphasia and whose first language is not English, but failed to identify that the MMSE is not standardised for people with learning disabilities who make up 2% of our population. The fact that this group of people, with a high prevalence of dementia, was completely ignored within the guidance is quite worrying. We appreciate that the guidance from NICE is not prescriptive and does not replace individual judgement; however, complete omission of learning disability could potentially exclude people from receiving beneficial treatment.