Aging

Psychological studies of aging populations began in earnest in the late nineteenth century when psychologists found that certain mental abilities deteriorated with age. These abilities included memory and the types of mental performance measured in IQ tests. In some individuals, verbal abilities were shown to deteriorate with advanced age, although at a slower rate than other skills; with others, verbal abilities, especially vocabulary, may increase with age. Such data have often been verified in tests with chimpanzees, where younger animals perform better in tests of memory and other such areas of mental functioning. For decades, then, it was assumed that the physical deterioration of the body, so evident in the elderly, was surely matched by a similar decline in the mind.

Recent studies, however, have begun to cast doubt on these assumptions. One area where current research has disproved a long-held belief about the aging of the mind is in the death of neurons, formally thought to necessarily lead to diminished mental functioning. It is now known that the brain has far more neurons than it could ever use, and that as they die their functions are taken over by nearby neurons. Scientists have recently proven that although abilities such as short-term memory and performing certain specific tasks within a time constraint often deteriorate after mid-life, other areas of mental activity, such as wisdom and judgment, become more acute and powerful.

In some cases, there is no change to mental function with age. Still other studies have shown that brains in older subjects are capable of performing many tasks as quickly and efficiently as brains in younger subjects, although the tasks are performed using different areas of the brain. For instance, research conducted at the Georgia Institute of Technology studied typing speeds in accomplished typists of college age and another group in their sixties. Common sense suggests that the older typists would perform less well because of decreased hand-eye coordination and slower reaction time. Surprisingly, both groups typed at the same speed. Researchers explained the results by pointing out that assumptions about declining dexterity and response time with age were correct, but that the older typists had made efficient adjustments in their methods, such as making fewer finger movements and reading ahead in the text, to compensate for any deficiency in those areas.

Fifty seems to be a crucial age in determining the brain's pattern of aging. Once a person has passed that age, brain functioning and mental ability are thought to be determined by essentially three factors: mental habits, chronic disease, and the mind's flexibility.

The elderly populations of many Western countries are the fastest growing segment of the population. In the United States, it is estimated that by 2030, more than 19% of the U.S. population will be age 65 or older. According to the Administration on Aging, that will total about 72 million Americans, more than twice the number of seniors in 2000. Among the elderly, the fastest growing population is people over 85.

As an increasing ratio of the population becomes older, attention will focus on the process of aging and the psychosocial problems faced by some of the elderly. Perhaps the most common psychological disorder often associated with aging is depression, and older adults are at a higher risk for depression than younger adults. One reason could be that at least 80% of all adults have at least one chronic health condition to deal with and nearly half of all older adults have at least two health problems to manage. Still, the Centers for Disease Control and Prevention estimates that major depression among the elderly averages less than 5% for all older adults.

Depression rates increase for the elderly who are ill enough to remain hospitalized or require home health care. And even though major depression rates are low, it is likely that many older adults may deal with an anxious or depressive episode at times. Having more frequent illnesses or losing the ability to complete some tasks on one's own and be as active as when younger can contribute to depression and anxiety. Often, major depression is not diagnosed correctly or undertreated in older adults.

With the increase in the aging population, more focus is being placed on geriatric mental health issues, including mental health support for older people who have disabilities and chronic health problems, those who live alone or in assisted housing, and elderly dealing with depression, loss, pain, or Alzheimer's disease and other dementias, for example. Research is revealing the importance of remaining physically and mentally active to retain cognitive function. In other words, the more an aging person works his or her brain, the better the brain continues to perform. The nation's 78 million American baby boomers are expected to crave more vitality and longer life, which could contribute to a healthier version of aging.