<p>The current demographic literature on ageing and intellectual disabilities indicates an increase in longevity for people with such disabilities, as a result of medical advances and better living conditions (Whitehouse and Chamberlain 2000). As more people with intellectual disabilities survive into old age, dementia is becoming an increasingly important issue for services, with prevalence rates for dementia at least twice as high in people with intellectual disabilities compared to the general population (Patel et al 1993).</p>