Dementia is a broad category of brain disease that includes any disease that causes loss of cognitive ability (the ability to think and reason clearly) that is bad enough to affect a person’s daily functioning. It must also be a worsening of functioning compared to how the person was previously. The most common form of dementia is Alzheimer’s Dementia (75%). Other common forms of dementia include: Dementia with Lewy Bodies, Vascular Dementia, Frontotemporal Dementia, Progressive Supranuclear Palsy, Corticobasalar Degeneration, Normal Pressure Hydrocephalus and Creutzfeldt-Jakob Disease.
Dementia is a disease that becomes more common with age. While only 3% of people between the ages of 65-74 have dementia, 47% of people over the age of 85 have some form of dementia. Therefore, as more people are living longer, dementia is becoming more common.
In DSM-5 the decision was taken to rename the dementias as neurocognitive disorders, with various degrees of severity.