Registered Nurses' Association of Ontario

Nursing Best Practice Guidelines

What is Dementia?

Dementia is a syndrome of progressive decline in multiple areas of cognitive function eventually leading to a significant inability to maintain occupational and social performance. The estimates of the prevalence of dementia range from 2.4 percent among persons aged 65-74 years, to 34.5 percent among those aged 85 and over (Loney, Chambers, Bennett, Roberts & Stratford, 1998). Research shows there are presently over 250,000 seniors with dementia in Canada, and it is estimated to rise to 778,000 by 2031 (Canadian Study on Health and Aging, 1994b; Patterson et al., 2001).