Age does not automatically bring cognitive decline, according to research reported in the November 2011 issue of Age and Ageing. The research, by scientists at the Institute for Aging Research of Hebrew SeniorLife, together with colleagues at Duke and Rush Universities, indicates, in fact, that two out of every three older adults experience only a trivial amount of decline in cognitive performance over late-life decades. The findings challenge widely held beliefs about cognitive decline and aging.
Institute researchers analyzed data from a large study involving more than 1,000 adults 56 to 102 years of age. Study participants were followed for up to 15 years and their cognitive performance was measured annually.
Using those data, the researchers classified participants as having slow, moderate, or rapid cognitive decline. Cognitive scores were determined by a scoring system that differed from, but can be compared with, IQ scoring: If 100 is average, the normal range falls between 70 and 130. For participants in the slow-decline group, this would mean that between ages 75 and 90, their cognitive score would be expected to dip from 100 to 94. For participants in the moderate-decline group, their cognitive score would be expected to change from 100 to 75 over the same age span, while participants experiencing rapid decline would be expected to move from 100 to 57 during those 15 years.
The findings carry implications for the care of seniors. Currently, cognitive decline is assumed to be a part of normal aging, which can lead to clinicians translating poor mental performance by elderly patients as something to be expected. With the knowledge that such decline is not a given, say the researchers, poor performance can be investigated, and preventable or reversible conditions, such as delirium, medication side effects, or vitamin deficiency, can be properly addressed.