Dementia is a progressive, disabling, chronic disease affecting 5% of all persons above 65 and over 40% of people over 90 years. The term dementia refers to a combination of symptoms involving impairments of memory, speech, thought, perception and reasoning. Early impairments in performing complex tasks lead to an inability to perform even the most basic functional activities such as washing and eating. Often there are changes in personality, behaviour and psychological functioning, such as depressive symptoms, apathy and aggression.

The most prevalent type of dementia in the elderly is Alzheimer's Disease. Two thirds of older people and one-third of younger patients (50-65 years old) with dementia have AD. We propose to develop COGKNOW in a cohort of AD patients with mild impairments in cognition and function. AD sufferers represent by far the most common cause of dementia throughout Europe and display a clinical course that is typically only slowly progressive. This allows the user to enjoy the eventual benefits of COGKNOW over a longer timeframe (until that point is reached when severe disability intervenes) and also permits better standardisation during COGKNOW field trials where a rapidly fluctuating clinical course might impede the assessment of user need and system efficacy.

Demographic changes mean that the countries of Europe can expect a massive rise in the number of older people and a corresponding increase in the number of dementia sufferers. If one considers the associated costs of community-based caring strategies and the emotional and economic burdens associated with institutionalisation, it is clear that these individuals must be considered in the context of both national and European healthcare strategies, as well as social and economic policies.