Senility reconsidered. Treatment possibilities for mental impairment in the elderly. Task force sponsored by the National Institute on Aging.

The brain is particularly vulnerable to insults occurring anywhere in the body. In some older persons, the brain may respond to insult by slowly developing impairment of intellectual functions (dementia) or abruptly showing significant changes in mental state (delirium). Sometimes the two coincide, producing a variable clinical picture with features of both dementia and delirium. It is crucial for health professionals, public planners, and lay persons to recognize that many curable physical and psychological diseases in the elderly produce intellectual impairment that may be hard to distinguish from irreversible brain disease.