What causes dementia? - Queensland Brain Institute - University of ...

  1. Dementia is a loss of mental ability severe enough to interfere with normal activities of daily living, lasting more than six months, not present since birth, and not associated with a loss or alteration of consciousness.
  2. Dementia is a broad category of brain diseases that cause a long term and often gradual decrease in the ability to think and remember that is great enough to affect a person’s daily functioning. Other common symptoms include emotional problems, problems with language, and a decrease in motivation. A person’s consciousness is usually not affected. A dementia diagnosis requires a change from a person’s usual mental functioning and a greater decline than one would expect due to aging. These diseases also have a significant effect on a person’s caregivers.The most common type of dementia is Alzheimer’s disease, which makes up 50% to 70% of cases. Other common types include vascular dementia (25%), Lewy body dementia (15%), and frontotemporal dementia. Less common causes include normal pressure hydrocephalus, Parkinson’s disease, syphilis, and Creutzfeldt–Jakob disease among others.