A decline in memory and cognitive (thinking) function is considered by many authorities to be a normal consequence of aging.^{1, 2} While age-related cognitive decline (ARCD) is therefore not considered a disease, authorities differ on whether ARCD is in part related to Alzheimer’s disease and other forms of dementia³ or whether it is a distinct entity.^{4, 5} People with ARCD experience deterioration in memory and learning, attention and concentration, thinking, use of language, and other mental functions.^{6, 7}

ARCD usually occurs gradually. Sudden cognitive decline is not a part of normal aging. When people develop an illness such as Alzheimer’s disease, mental deterioration usually happens quickly. In contrast, cognitive performance in elderly adults normally remains stable over many years, with only slight declines in short-term memory and reaction times.⁸

People sometimes believe they are having memory problems when there are no actual decreases in memory performance.⁹ Therefore, assessment of cognitive function requires specialized professional evaluation. Psychologists and psychiatrists employ sophisticated cognitive testing methods to detect and accurately measure the severity of cognitive decline.^{10, 11, 12, 13} A qualified health professional should be consulted if memory impairment is suspected.

Some older people have greater memory and cognitive difficulties than do those undergoing normal aging, but their symptoms are not so severe as to justify a diagnosis of Alzheimer’s disease. Some of these people go on to develop Alzheimer’s disease; others do not. Authorities have suggested several terms for this middle category, including “mild cognitive impairment”¹⁴ and “mild neurocognitive disorder.”¹⁵ Risk factors for ARCD include advancing age, female gender, prior heart attack, and heart failure.