Alzheimer's disease is the most common cause of dementia in older people, with about half a million people affected in the UK. Its effects are devastating and far-reaching for sufferers, their carers and society in general – the Audit Commission estimated the annual cost of dementia care for 1998–1999 at £6.1 billion (Audit Commission, 2000). There is no cure and it is terminal within 3 to 7 years of diagnosis. Given an estimated doubling of dementia cases over the next 50 years (Melzer et al, 1997), the burden of care is set to increase substantially.