Dementia is a decline in mental ability which affects memory, thinking, problem-solving, concentration and perception. Some forms of dementia, such as Alzheimer's disease, are degenerative i.e. they get worse over time. Other forms of dementia, such as vascular dementia, may be non-degenerative i.e. they may not get worse over time.

People with dementia can become confused, leading to restless or repetitive behaviour, which can be very distressing for everyone concerned. They may also seem irritable, tearful or agitated. They may also develop other problems such as depression, disturbed sleep, aggression, inappropriate sexual behaviour and incontinence.

Dementia is almost invariably a disease of ageing. About one in 20 people over the age of 65 are affected, and one in five people over the age of 80. Dementia in people under 65 is known as early onset or pre-senile dementia and is rare, affecting under one in 1000.

For further information please contact

Alzheimer's Society

Devon House, 58 St Katharine's Way, London EW1 1LB

Phone number - 020 7423 3500

Helpline - 0845 300 0336

Fax - 020 7423 3501

Web - http://www.alzheimers.org.uk