Dementia is thought to occur as a result of nerve cell damage within the brain. This damage interrupts the transfer of information between brain cells and, as a result, a person’s thinking and behaviour is affected. Why this happens for some people and not for others however is not yet known, but there are a number of factors that might play a role in the development of the disease.
Age itself remains the greatest single risk factor for the development of dementia, with approximately seven per cent of individuals aged 65 years or over, and 40 per cent of individuals over the age of 85, having some form of dementia.
Younger onset dementia, which develops before age 65, is becoming both more commonly diagnosed and better-studied. Younger onset dementia is associated with specific age-related adverse consequences for both younger individuals and their families, including depression and social isolation. Genetic factors and family history also play a role in nearly all forms of dementia.
In addition, a range of lifestyle factors have been associated with an increased risk of developing dementia. These include smoking, lack of regular exercise, being overweight or obese, and lack of mental stimulation or social interaction. A variety of psychological and physical health factors are also thought to increase the risk of dementia, including depression, diabetes, high cholesterol, high blood pressure, heart disease and stroke.