Aging

The process by which the human body changes and matures over time, especially the means by which dying cells are not replaced in sufficient numbers to maintain current levels of function; the process by which human behavior alters with time.

Psychological studies of aging populations began in earnest in the late nineteenth century when psychologists found that 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 corroborated 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 while abilities like 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. 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 the assumptions about dexterity and response time were correct, but that the older typists had made clever, efficient adjustments, such as making fewer finger movements and to read ahead in the text, to compensate for their 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 the year 2030 there will be 50 million persons over age 65. Among the elderly, the fastest growing population is people over 85. Such demographic data will continue to focus attention on the process of aging and the psychological problems faced by the elderly. Perhaps the most common psychological disorder often associated with aging is depression. According to the National Institute of Mental Health, depression among the elderly range from 10 to 65 percent. Suicide rates among the elderly have been increasing at alarming rates. A study conducted by the federal government found that between 1980 and 1986, suicides by persons aged 65 and older increased 23 percent among white men, 42 percent among black men, and 17 percent among white women. The highest suicide rates are for white men over age 85. The elderly comprise about 13 percent of the nation's population (one in eight Americans) and account for about 20 percent of all suicides.

With the increase in the aging population, more focus is being placed on geriatric mental health issues, including disabilities since more than half the population has at least one, chronic health problems, living alone or in assisted housing, depression, loss, pain, Alzheimer's and dementia, among others. 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.