 The rise in life expectancy in recent decades has resulted in a dramatic increase in the population of older people. This has been associated with a rise in the prevalence of age-associated conditions, particularly cognitive impairment and dementia. The prevalence of dementia in those older than 65 doubles every five years, and reaches a rate of more than 40 at age 85 years. Data from the World Health Organization predict 43 million dementia sufferers globally in the year 2020. 