The outline of articles that follows was compiled by the editors to provide readers with an overview of the encyclopedia's coverage of topics in aging. This systematic list is intended to be helpful in developing courses, pursuing research, or simply browsing in a particular area of gerontology or geriatrics. Readers seeking a particular topic should consult the index of this enc…
Animal models have been used to study accelerated aging, accelerated senescence, premature aging, premature senescence, and progeria-like syndromes. These models may be grouped into four classes: (1) experimentally induced models, (2) gene-modified models, (3) selection models, and (4) spontaneous models. There has been much debate over the connection between accelerated aging and disease status i…
Human aging is a complex process resulting from the interaction between a person's genetic makeup, their environment, and time. Individuals mature to adulthood, then undergo a gradual degenerative process that eventually results in death. Most of us go through these processes at roughly equivalent rates; indicating that a carefully controlled developmental program operates until adulthood. …
The National Adult Day Services Association (NADSA) defines an adult day center in its Standards and Guidelines for Adult Day Services (revised 1997) thus: An adult day center is a community-based group program designed to meet the needs of adults with functional impairments through an individual plan of care. This is a structured, comprehensive program that provides a variety of health, social a…
Adult protective services represents the constellation of interventions used to promote safety and well-being for older persons (or other vulnerable adults) whose health or circumstances subject them to harm or threat of harm. Protective services have evolved since their origins, with current focus on elder abuse broadly defined. Most of the work, however, is directed at the needs of older persons…
Since the mid-1970s, much attention has been focused on the topic of advance or prospective health care planning. This activity has been promoted as a way for individuals to maintain some control over their future medical treatment even if they become physically and/or mentally unable to make and convey important decisions regarding issues of care. Advocates of advance health care planning also cl…
The idea of old-age–based rationing of health care in the United States began to emerge publicly in the 1980s and has been hotly debated ever since. In a 1983 speech to the Health Insurance Association of America, the economist Alan Greenspan pointedly wondered "whether it is worth it" to spend nearly one-third of Medicare, a federal program that provides national health insur…
Age discrimination occurs when individuals are treated differently because of their chronological age. Children and youth are routinely treated differently than adults. They are required by law to attend school and denied the legal right to vote, drink alcohol, and work. This type of age discrimination is justified because of children's immaturity. Although people debate the chronological a…
There are two distinct but related meanings of "age integration." First, it means breaking down age barriers; people's ages are not used to dictate what positions or roles they can hold or must give up. The second meaning of age integration is "cross-age interaction": people of different ages doing something together, such as working, learning, or having fun. The…
The term ageism refers to a deep and profound prejudice against the elderly (Butler). In simple terms, ageism occurs when people stereotype others based on old age. Ageism occurs throughout society in varying degrees, in television, advertising, movies, stores, hospitals, and jobs. Ageism is a process of stereotyping and discriminating against people because they are old. From a definitional per…
Hopkins (CEO of large American broadcasting company): ". . .you're at an important stage of your career. How old are you?" Rath (Hopkins's assistant): "Thirty-three." Hopkins: "That's an important age. In the next six or seven years, you should really be on your way." (Wilson, p. 224) Hopkins, a fictional character from Sloan Wilson&#x…
The age-period-cohort model is a theoretical model that aims to explain how society changes. In this model, variation over time is thought to occur because of the simultaneous operation of three factors: individual aging, period influences, and generational (or cohort) turnover. Popular theories of social change rest on the idea that culture, social norms, and social behavior change through two …
We tend to think of aging in terms of human beings living in time, and, in particular, as the chronology of human experience in later life. But human aging is set in a much wider context, encompassing the biological, geological, and cosmological spheres. Aging is the elegant and continuous means by which the forces of nature, from the microscopic to the universal, create the conditions for regener…
Older people overwhelmingly prefer to age in place—to stay in their homes or apartments as they age, rather than move to new settings. Most of them do so: fewer than 10 percent live in nursing homes, assisted living or adult foster care facilities, or continuing-care retirement communities. In fact, during the 1990s, the number of people living in nursing homes in the United States declined…
Alcoholism is an illness that is a common form of chemical dependence, and is often referred to as a substance abuse disorder. As with any behavioral disorder, some people are predisposed to it, but there are also strong cultural and environmental influences. Alcoholism is associated with many poor health outcomes. Alcoholism can be tricky to define, in part due to cultural variability in what is…
Many older persons fall within the protections of the Americans with Disabilities Act (ADA), which was enacted by Congress as Public Law no. 101-336 on 26 July 1990 and signed by President George Bush, becoming effective in 1992. This legislation was intended primarily to expand to almost the entire public and private sectors the requirements regarding rights to employment, services, and public…
"My diseases are an asthma and a dropsy and, what is less curable, seventy-five." —Samuel Johnson. Over 40 percent of all surgical procedures in the United States are performed on patients over age sixty-five, a remarkable statistic given that those over sixty-five comprise only 13 percent of the U.S. population. Elderly patients are more likely than their younger counterpart…
The Spanish explorer Ponce de Leon was looking for the Fountain of Youth when he sailed across the Atlantic to the New World, and antiaging researchers continue the perennial quest (Van Tassel). It is also a quest that has attracted numerous venture capitalists and is the focus of a myriad of biotechnology companies. A definitional distinction is necessary here. The life expectancy of any species …
Anxiety is a normal part of life, and it occurs over the entire life span. In particular, the experience of anxiety continues into later life. Just as younger people worry about things important to their stage of life, such as school, job, finances, and family, so too do older adults worry about health, family, finances, and their mortality. Elderly persons are as likely to react with fear or pani…
In 1965, when the Older Americans Act (OAA) was passed, all aging program allocations went from the State Unit on Aging (SUA) in each state directly to service providers. During the late 1960s and early 1970s, social movements precipitated a move towards community-based planning for government-funded programs. The result of this shift was that local decision-making occurred at the regional, rather…
Comprehensive Geriatric Assessment (CGA) is the term most commonly used to refer to the specialized process by which the health of some elderly people is assessed. CGA has four characteristics: To consider this process in more detail, we can examine each of the items identified in the opening sentence: Some people, are assessed, by a specialized process. CGA is not meant for all elderly people, o…
Autonomy expresses the idea that persons should direct their own actions and be free from coercion or undue influences by others on their actions and deliberations. The concept of autonomy has touched all areas of social life and has had a pronounced effect on medical ethics and medical practice. Patient autonomy emerged in the 1960s and 1970s in the great social movement that created a diverse ra…
Baby boomers are all those born in the United States between 1946 and 1964. As illustrated in Figure 1, in the post–World War II period the General Fertility Rate (GFR) in the United States rose from what had been an all-time low in 1936 of 75.8 children per 1,000 women of childbearing age to a high of 122.7 in 1957—and then fell to a new all-time low of 65.0 in 1976. All races, reli…
The ability to stand and walk, often taken for granted, is necessary for full independence in daily activities and integration in society. Balance and mobility often decline with aging, and specific diseases also lead to deficits. The contracted living space, need for care, falls, and injuries that result from this decline are important sources of illness in older persons, are costly to society, a…
Behavior management refers to a class of therapeutic techniques for altering behavior by changing one or more aspects of an individual's environment. The aspects that are changed are those believed to contribute most significantly to the occurrence or maintenance of behaviors that are problematic for the individual himself/herself or for other individuals in the environment. Environmenta…
For older Americans, the loss of a loved one is a relatively common occurrence, yet it is often severely distressing and can have dire implications for mental and physical health. Over two million people die in the United States each year. Each of those deaths leaves behind a wake of grief that ripples through a web of surviving family Photographer Edward S. Curtis called this 1924 photograph…
The process (processes) of aging is a complex phenomenon. Aging in the biological sense is the loss of the ability to maintain homeostasis, that is, the loss of the ability to meet challenges from the environment, such as heat or cold or infection, by overcoming the challenge and restoring normal function. Loss of homeostatic ability can occur at the level of the whole organism or in one or more o…
Humans and other vertebrates possess a central nervous system (CNS)—the brain and spinal cord—containing specialized cells called neurons. The nervous system is essential for virtually every aspect of life and, along with the body's other systems (muscular-skeletal, endocrine, etc.), performs the following seven basic, interrelated tasks: It is evident from our everyday observ…
The 2001 census found that Canada has a population of 31 million people who are heavily concentrated in communities located within 100 miles of the Canada–United States border. There is further concentration of the population in cities and towns, as over 60 percent of all Canadians live in the twenty-five metropolitan areas that have populations of over 100,000, and 80 percent live in urban…
Canada is a parliamentary democracy in which the division of powers between the federal and provincial governments determines how health and social support services are funded and administered. The division of powers between the federal and provincial governments for health and social services was originally prescribed in 1867 in the British North American Act (BNA Act). This distribution of autho…
Means-tested and social insurance programs have evolved to provide income support to people who cannot, or are not expected to, support themselves. Thanks to old-age income protection schemes, typically referred to as social security, growing numbers of men and women around the world face an economically secure old age, free of work. Between 1940 and 1999, the number of countries with programs tha…
Complex multicellular organisms contain two basic classes of cells: mitotic and postmitotic. Postmitotic cells cannot divide, although they may function throughout adult life. Examples of postmitotic cells include mature neurons, adipocytes (fat cells), and mature muscle cells. Mitotic cells, by contrast, retain the ability to divide throughout life. Mitotic cells may divide continually, or they m…
While the group of Americans sixty-five years or older comprise about 13 percent of the population, 60 percent of all newly diagnosed cancers and 70 percent of all deaths from cancer occur in this age group, emphasizing the magnitude of this disease in older adults. All the major cancers primarily affect older adults, with the risk of developing cancer increasing as age increases. Of the most comm…
When they are placed in a culture environment, human cells exhibit a finite proliferative capacity and are usually able to divide only forty to sixty times before reaching a senescent (nondividing) phase. The limited proliferative capacity of human cells in a culture environment is thought to result from multiple environmental and genetic mechanisms, and has been widely used as a model of human ag…
Development proceeds through many steps that ultimately produce germ (reproductive cells) and somatic (nonreproductive) cell lineages. The germ cell lineage population is potentially immortal, because the genes it carries can be passed on indefinitely. The somatic cells will ultimately age and die. Early studies by Carrel and coworkers suggested that, when isolated from organisms, individual somat…
Many, if not the majority, of genetic loci in individuals in outbred, or wild, populations (including human) can have alternative versions of the gene, called alleles, that may or may not specify different genetic information. The term genetic polymorphism is used to describe a Mendelian trait that is present in at least two phenotypes (the observable physical characteristics of an organism) that …
Aging is a complex process that occurs on multiple levels. The end result of aging is that life span is limited in multicellular organisms. The cells that make up multicellular organisms also have limited life spans. The limitation on cellular life span is comprised of two parts: (1) cells become unable to continue dividing but remain metabolically active, and (2) at some future time cell death oc…
Cholesterol, cholesterol esters, and triglycerides are fats, or lipids. On their own these would not be soluble enough to circulate, so to circulate in blood, these lipids are combined with phospholipids and protein in particles called lipoproteins. Generally, only three lipoproteins—very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL)…
Circadian rhythms (from circa [approximately] and dies (day)) are internally generated, near-24-hour fluctuations in physiology, performance, and behavior. Circadian rhythms have been identified in nearly every species in which they have been examined, from unicells to plants to mammals. Circadian rhythms are thought to provide an adaptive advantage to the organism by providing it a means to antic…
Cognitive-behavioral therapy (CBT) is a combination of cognitive and behavior therapies that are directive, time-limited, structured, and place great emphasis on homework exercises. While cognitive therapy emphasizes the role of cognitive processes in the origin and maintenance of psychological disorders, behavior therapy focuses on principles of learning theory and the role of reduced reinforceme…
The concept of cohort change, which is an attempt to link the "biological rhythm of human existence" (Mannheim, 1952) with the "evolution of the social order" (Parsons, 1951), is a prime example of a tool designed to analyze linkages between the micro (i.e., individual) and macro (i.e., societal) levels of human reality. The phenomena of cohort replacement creates oppor…
The determination of competency is a critical one in a liberal democracy as it tries to balance the values of self-determination and the protection of innocents from harm. This determination becomes particularly important in elderly persons for whom chronic illness and mental disability both necessitate and frustrate decisions about medical treatment, about institutional placement, and, sometimes,…
As people live longer, some fear that they will spend additional years in poor health, disabled, and demented. In contrast, the compression of morbidity hypothesis (1980) posits that people can have both a longer life and a healthier old age. To do so, it is necessary to postpone the onset of morbidity (e.g., disability), through healthy preventive practices, more rapidly than death is postponed. …
The Nutrition Program for the Elderly (NPE), part of the Older Americans Act (OAA) grants for state and community programs on aging, helps ensure a healthy, well-balanced diet for older Americans. Through this program, seniors who might otherwise be isolated and lonely, or who cannot afford to buy or prepare meals for themselves, do not have to go without food. They can eat a meal and socialize wi…
The term congregate housing has both generic and specific meanings. Generically, it refers to multiplex-unit, usually planned, supportive housing for older people (and younger people with disabilities) who need or want assistance with daily activities. Seen as a more independent option than an assisted living or skilled nursing facility, congregate housing typically provides services such as house…
Constipation is a very common presenting symptom in elderly people. There are two reasons for this: (1) bowel function and defecation become less satisfactory with advancing years, since emptying may be incomplete and the presence of a small residue of feces may cause continuing discomfort; and (2) uncertainty as to what constitutes a normal bowel pattern may create anxieties about disease or othe…
According to the definition developed by the National Institute on Consumer-Directed Long-Term Services, consumer direction of long-term care services, or consumer-directed care, is both a philosophy and a practice model for home care. As a philosophy, it emphasizes consumer choice and control, recognizing that service recipients themselves are the ones who best know their needs and preferences an…
The U.S. Consumer Price Index (CPI) is a measure of the average change in the prices paid by consumers living in urban areas for a bundle of consumption goods and services. Average price changes can be driven by changes in consumer income, population and demographic changes, and changes in consumer preferences, as well as by the introduction of new product distribution patterns and marketing techn…
Simply defined, consumption is household spending on consumption goods and services. However, consumption can also be defined as the satisfaction obtained by consumers from the use of goods and services. A person's life-cycle stage is usually regarded as the most important predictor of consumption. Households headed by young people usually spend less than average on products and services be…
Healthy and successful individuals often have a strong sense that they are in control of their lives and the world around them. Likewise, men and women who feel that they are in control of their lives tend to be healthy and successful. An individual's perception of his or her ability to be effective in the world, what psychology textbooks refer to as perceived control, is widely studied bec…
Over the course of the twentieth century, dramatic changes occurred in the coresidential patterns of older Americans. Between 1900 and 1998, the percentage of elderly persons living alone increased five-fold, rising from 5 percent to 26 percent. This historical rise in living alone has been attributed to three basic mechanisms that reflect a long-term change in the status and well-being of older p…
Creativity is most often defined as the individual capacity to generate ideas that are both original and useful. Thus, those who have highly novel but clearly maladaptive ideas are not considered creative. An example would be paranoid psychotics whose delusions of grandeur and persecution prevent them from leading normal lives. By the same token, in everyday life there are numerous solutions to pr…
Creutzfeldt-Jakob disease is one of the transmissible spongiform encephalopathies, a family of diseases affecting humans and animals (see Table 1). They are transmissible, in that susceptible animals inoculated with diseased tissue will develop a similar disease; spongiform, in that, under a microscope, small spaces (vacuoles) in brain tissue are invisible, giving the appearance of a sponge; and e…
An eighty-year-old man is convicted of second-degree criminal solicitation for offering a substantial sum of money to have his business partner of forty years murdered. A woman, seventy-two years old, robs a female acquaintance, age ninety-one, at gunpoint. A restaurant supply delivery man argues with a bank security guard after double-parking his truck and blocking three of the bank's park…
Generally speaking, the term "critical gerontology" can be used to describe a rather broad spectrum of theoretical interests, ranging from constructions and deconstructions of aging (Gubrium, 1986; Hazan; Katz) to the issue of power and control in contemporary society (Estes; Moody, 1988, 1993; Phillipson and Walker). What ties these different perspectives together is that all of the…
Cultural diversity, as it relates to aging, connotes variety among the older adult population in racial, gender, social, economic, religious, health, and other characteristics. The present discussion focuses primarily on the demographic characteristics of race, ethnicity, and national origin as they relate to selected aspects of the aging process. The U.S. Bureau of the Census recognizes four dist…
Geriatric day hospitals have been part of the health care of older adults for many years. The global increase in the number of older adults has combined with fiscal pressures to decrease lengths of stay in acute care facilities and resulted in shortages of long-term care space in most developed countries. Day hospitals are intended to serve as a midpoint between acute care and out-patient rehabili…
Dying and death are profound aspects of the human experience. Social science research documents the fact that defining someone as "dying" is a social process. Although critical medical conditions certainly have a physiological basis, disease states are given significance through interpretation (Muller and Koenig). Perceptions that dying has begun and the meanings associated with …
Delirium is a derangement of mental function characterized by disturbance of consciousness and impairment of cognition. In contrast to dementia, delirium usually develops over a short period of time, it tends to fluctuate in severity over the course of the day, and it usually resolves with treatment of the underlying causes. This disturbance of consciousness results in reduced awareness of the ext…
The word dementia comes from Latin and means "out of the mind." It is used to describe an acquired, persistent, global impairment of cognition/intellectual processes, which is sufficiently severe to interfere with social or occupational function. Dementia, like delirium, is known as a syndrome, that is, it is a collection of symptoms and signs, whose presence can be diagnosed, but t…
There has been much progress in the ethics of dementia care. Dementia is a syndrome (i.e., a cluster of symptoms) that can be caused by a myriad of diseases. The most common disease cause of irreversible, progressive dementia is Alzheimer's disease, which this article will frequently allude to. Moral progress is evident in the fact that the use of physical restraints is diminishing in nurs…
Dementia with Lewy bodies is a comparatively new diagnostic entity. Formal criteria for its diagnosis have existed only since 1992. Even now, changes in neuropathological techniques for its recognition are changing the understanding of how commonly this disease occurs. Depending on the study, it may vie with fronto-temporal dementia as the next most common neurodegenerative cause of dementia after…
Various forms of clinical depression are defined by the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM IV). According to this classification scheme, five or more symptoms (see Table 1) must be present during the same two-week period, and they must represent a change from previous functioning, in order for a person to receive a d…
Developmental psychologists are interested in time- and age-related changes in cognitive and intellectual functioning, personality, and social relationships from birth to death. Theory and research deal with three core phenomena: general principles of developmental change, individual differences in development, and intervention possibilities. Two research designs are used to examine these phenomen…
A developmental task is one that arises predictably and consistently at or about a certain period in the life of the individual (Havighurst, 1948, 1953). The concept of developmental tasks assumes that human development in modern societies is characterized by a long series of tasks that individuals have to learn throughout their lives. Some of these tasks are located in childhood and adolescence, …
Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEA-S) are the most abundant steroids produced by the human adrenal gland. DHEA-S, sometimes considered as a plasma "reservoir" for the hormone, appears in the circulation at about one thousand times the concentration of DHEA, is water soluble, and is capable of being bound to albumin. Although it is DHEA that has bee…
Diabetes mellitus is a failure to control blood sugar levels so that they become too high. It is classified into two categories. Type 1 diabetes (also called juvenile diabetes) is characterized by an acute destruction of insulin-secreting beta cells in the pancreas by autoantibodies. Insulin is a hormone essential to maintaining blood sugar at a normal level. Diabetes results in the abolition of i…
The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, DSM-IV published by the American Psychiatric Association (APA) in 1994, acts as a comprehensive guide to the nomenclature, classification, and diagnostic criteria for mental disorders in the United States. Used widely for research, clinical, and statistical purposes, the DSM-IV provides a systematic method to form psy…
Much was learned in the twentieth century about disease and how it presents in children and adults. Traditional medical teaching emphasizes specific disease symptoms and signs that point to a specific diagnosis. However, in the last several decades it has become apparent that common diseases often present differently in older adults. This has lead to the concept of so-called atypical disease prese…
The year 1961 was a watershed in the emergence of theory in the field of aging. That year saw the publication of Elaine Cumming and William Henry's book Growing Old, in which the term disengagement was introduced. This was the first time a distinct theory of aging emerged in scientific form, signaling the beginning of theoretical consciousness in social gerontology and setting the stage fo…
Divorce is a major stage in life for large numbers of older men and women in the United States (and many other countries). For example, in the United States in 2000, there were more than a million women over the age of sixty-two who were either divorced or separated. Until now this group of women has been relatively invisible within the elderly population. Difficult as it is to believe, few stati…
Divorce is the voluntary, legal termination of a marriage. To understand how divorce influences the aging experience, a life-course perspective is particularly informative. A major tenet of this approach is that history shapes an individual's life experience. In terms of divorce, this is certainly true, as documented by the variations in divorce statistics by historic period and birth cohor…
Dizziness is a common medical problem. Thirty percent of people over age sixty-five complain of dizziness and 20 percent of all older persons experience dizziness severe enough to seek medical advice. The syndrome of dizziness is varied and encompasses a wide range of symptoms. Getting a precise and accurate description of the individual's symptoms is therefore essential for making an accur…
DNA is the master molecule and serves as the blueprint for the formation of all proteins and enzymes in every organism. The proteins then generate all the other substances in our cells. Thus, it is essential for reproduction, growth, and maintenance, and for sustaining normal living, that the DNA remains intact so that the genetic code can be read correctly. The stability and intactness of the DNA…
Transportation is a critical link for independent living and healthy aging; and for many people in the United States, transportation is defined as driving. Whether it is a trip to the grocery store, to volunteer, to see a doctor, to visit a friend, or to simply experience the joy of getting out, the automobile is the means for most people to remain active and healthy contributors to society. Moreo…
The road to drug development is a long and demanding process that can take up to 15 years. Before a substance is deemed "safe" it must go through the series of phases shown in Figure 1. These phases are called: discovery; preclinical testing (in animals); phase I; phase II; phase III; review by the U.S. Food and Drug Administration (FDA); and phase IV. During Phase IV the drug becom…
Medication use by older people continues to receive attention in the lay media and in medical literature. People age sixty-five and over make up approximately 13 percent of the total population, yet they consume about 40 percent of all medications (Jones-Grizzle et al.). This rate of medication use among seniors coincides with the rate of many chronic diseases, which rise sharply with age. For exa…