How is dementia defined? How do definitions vary?
Dementia is generally regarded as an acquired loss of cognitive function due to an abnormal brain condition.
The National Institutes of Health criteria (formerly the National Institute of Neurological and Communicative Diseases and Stroke-Alzheimer’s Disease and Related Disorders Association or NINCDS-ADRDA criteria) for the diagnosis of Alzheimer’s disease (AD) stressed that there must be progressive loss of cognitive function, including but not limited to memory loss.
A recent revision of these criteria puts less emphasis on memory impairment. The DSM-IV general criteria for dementia included the requirement of functional decline that interferes with work or usual social activities in addition to cognitive decline.
DSM-5 now calls this major neurocognitive disorder instead of dementia .
