Huntington's disease is a progressive hereditary disease. It usually becomes apparent in adults in their 30s, although it can occur earlier or later. There is also a juvenile type of Huntington's, which affects children. The course of the disease varies for each person, and dementia can occur at any stage of the illness.
Symptoms of dementia associated with Huntington's disease include loss of short-term memory and deterioration of planning and organisational skills. People with the disease usually lack insight into their condition and other people's needs, and may be reluctant to accept help. They may also develop obsessive behaviour. This form of dementia differs from Alzheimer's disease in that those affected continue to recognise people and places.
At present, the dementia associated with Huntington's is untreatable, but a great deal of research is being carried out.