More than 6 million people in the United States are currently living with Alzheimer’s disease, a number that will rise to nearly 14 million by 2060 if current demographic trends continue (Rajan et al., 2021; Matthews et al., 2019; Bynum and Langa, 2020; Zissimopoulos et al., 2014, 2018).1 It is estimated that approximately one-third of older Americans have Alzheimer’s or another dementia at death (Weuve et al., 2014). The economic cost of dementia in the United States has been estimated at $305 billion in 2020, and is projected to rise to $1.5 trillion by 2050 (Zissimopoulos et al., 2014; Alzheimer’s Association, 2021).2 The financial and emotional costs to patients and families are enormous and impossible to fully measure.
Dementia is a syndrome that can result from several different, often co-occurring, diseases, of which Alzheimer’s is the most common; see Box 1-1 for an explanation of the terminology used to refer to these diseases in this report, as well as other key terms used throughout the report (terms that have more specific application are defined as they appear). Most forms of dementia develop gradually, and changes in an individual’s functioning vary widely in pace and nature; moreover, each person living with dementia does so in a unique context. Regardless of the underlying causes, these diseases begin to affect people’s capacity to work and carry out other activities,
1 These figures are likely to be underestimates because they include only persons living with Alzheimer’s disease, not other forms of dementia.
as well as their relationships with loved ones, friends, and coworkers. Those who live with and care for individuals experiencing these diseases face challenges that include physical and emotional stress, difficult changes and losses in their relationships with life partners, loss of income, and interrupted connections to other activities and friends.
From a societal perspective, dementia places substantial demands on communities and on the institutions and government entities that support people living with dementia and their families—strains that are likely to
grow as the number of persons living with dementia rises. By 2034, people over age 65 will outnumber children under 18 in the United States, and by 2060, they will make up 23 percent of the U.S. population (Vespa, 2018). Thus, there will be fewer adult children to provide care, as well as a shortage in the supply of paid care providers (those who provide medical care and direct care).
Research in the biomedical sciences has made important contributions to understanding of the pathophysiology of Alzheimer’s disease and related
conditions, but this work has yet to be translated into effective preventive therapies or pharmaceuticals that can halt the progression of the disease or mitigate its impacts. Until recently, no new medications targeting dementia symptoms had been approved in the United States since 2005, and currently available medications offer modest benefits at best (Cummings et al., 2014). It is hoped that aducanumab, a drug that was recently approved by the U.S. Food and Drug Administration despite the objections of its advisory panel, may slow or temporarily arrest some symptoms of Alzheimer’s disease, but research has not yet demonstrated that it will have that benefit (issues surrounding the approval of aducanumab are discussed in Chapters 7 and 9). A wide array of social and behavioral influences has been associated with the risk of developing dementia, its trajectory, and the nature of the experience of living with the disease, as discussed in Chapter 2, but growing understanding of these influences has not yet led to the development of broadly effective interventions.
Thus dementia, with its profound impacts on individuals, families, and society, will be a fact of life for the foreseeable future. However, research in the social and behavioral sciences points to possibilities for preventing or slowing the development of dementia and for substantially reducing its negative impacts. This research can shed light on social, behavioral, economic, environmental, cultural, and other contextual factors that influence the development of the disease; its course; and its effects on individuals, families, caregivers, communities, and the health care system. Such research can be the foundation for strategies to address the challenges dementia brings and improve the lives of those affected by it.
In this context, the National Institute on Aging within the National Institutes of Health (NIH) of the U.S. Department of Health and Human Services requested that the National Academies of Sciences, Engineering, and Medicine conduct a consensus study to produce a decadal survey3 assessing the contributions of research in the social and behavioral sciences to mitigation of the negative impacts of Alzheimer’s disease and related dementias and identifying a research agenda for the coming decade. This effort complements an array of initiatives occurring as part of the National Plan to Address Alzheimer’s, a project of the U.S. Department of Health and Human Services.4
3 A decadal survey is a method for engaging members of a scholarly community to identify lines of research with the greatest potential to be of use over a 10-year period in pursuit of a particular goal. The National Academies developed this type of survey to support the planning of future research for government agencies and other entities.
The study charge, shown in Box 1-2, focuses on research that can improve the experience of living with dementia, so this report is concerned primarily with the impacts of dementia on those for whom symptoms have become salient and their caregivers (see Chapter 3). Issues related to diagnosis and recognition of early symptoms, people who are at risk for developing dementia, and those with conditions that can lead to dementia who are not showing symptoms are also important, and we touch on those as well.
To carry out this study, the National Academies convened the Committee on the Decadal Survey of Behavioral and Social Science Research on Alzheimer’s Disease and Alzheimer’s Disease-Related Dementias, whose members have expertise in sociology, epidemiology, biostatistics, public health, psychology, anthropology, geriatric medicine, psychiatry and neurology, bioethics, and public policy (see Appendix A for biosketches of the committee members). The project was supported by the AARP, the
Alzheimer’s Association, the American Psychological Association, The John. A. Hartford Foundation, the JPB Foundation, the National Institute on Aging, the National Institutes of Health, the Office of the Assistant Secretary for Planning and Evaluation within the U.S. Department of Health and Human Services, and the U.S. Department of Veterans Affairs. This report presents the committee’s conclusions and the evidence that supports them, which collectively provide the basis for a 10-year research agenda that can ultimately yield powerful benefits to people living with dementia, their caregivers and communities, and society.
As noted earlier, a decadal survey is a method for engaging members of a scholarly community to identify lines of research with the greatest potential impact over a 10-year period in pursuit of a particular goal. The National Academies developed this type of survey to support the planning of future research for a range of government entities with missions in the earth and space sciences, including the National Aeronautics and Space Administration, the National Science Foundation, the U.S. Department of Energy, the National Oceanic and Atmospheric Administration, and the U.S. Geological Survey. More recently, the decadal method was applied for the first time to research in the social and behavioral sciences in a study of research to strengthen intelligence analysis and enhance national security, which includes a detailed discussion of the National Academies’ decadal process (NASEM, 2019a; see also NASEM, 2015). Regardless of the field of study, decadal surveys are a powerful tool for identifying research whose relevance to policy priorities may have been overlooked, as well as for identifying key questions to answer in the coming decade.
The decadal process was developed to meet urgent public policy needs, and there are compelling reasons for viewing dementia in this light and launching the first decadal survey of research related to the lived experience of dementia. As noted above, the numbers of persons affected by dementia are large and growing rapidly, and the impact of these diseases on individuals and their families and on society is substantial. There is also strong evidence that members of some racial/ethnic groups, as well as economically disadvantaged populations, are at greater risk for dementia, and that the availability, quality, and financing of care may be more limited for these populations (Quiñones et al., 2020a, 2020b; Favreault et al., 2015). Attention to the rapidly growing challenges of dementia has increased. Congress sent a powerful message when it tripled research spending on dementia at the National Institute on Aging over the 3-year period 2015–2018. The only precedents for this level of increase at NIH were the war on cancer, initiated in 1971, and the dramatic expansion of AIDS funding in the late
1980s (Kaiser, 2018). However, this spending has targeted primarily biomedical research rather than research in the social and behavioral sciences.
The committee looked across the landscape of the social and behavioral sciences for research that could help to ameliorate what we understand to be the “burden” of Alzheimer’s disease and related dementias: their negative impacts on individuals, families, and communities, and the social and economic costs of ensuring that professional care and resources are available to people at all stages of disease. Researchers in social and behavioral fields are making a critical contribution to the overall landscape of dementia-related research by offering key pieces to the puzzle that biological and pharmaceutical research cannot provide. The past few decades have produced a vast amount of research on the biological mechanisms that lead to dementia, as well as potential pharmacologic interventions that can ameliorate that pathology. As noted above, however, no disease-altering medications—ones that can prevent, delay, or cure dementia—have been approved. The drugs that are available may mitigate symptoms of the disease but do not address its underlying causes. There is enormous interest in finding a drug for a common and fatal disease that causes so much suffering, but research outcomes to date have been disappointing. Although aducanumab may ultimately provide more benefit than many observers expect—or another new medication that effectively slows or prevents dementia may be discovered and approved in the next few years—dementia will not be eradicated by one or even several medications, for a number of reasons.
First, evidence suggests that many types of dementia are multifactorial. While the pathology of Alzheimer’s disease is common, it often occurs in conjunction with vascular and other pathologies. It is unlikely that a single medication will effectively eradicate all neuropathology, and indeed those medications under study are not designed to do so. Most medical advances—for instance, those related to cancer or HIV—occur when several interventions can be combined to address different aspects of a disease. Thus, multiple different successful discoveries may be needed to have a meaningful impact on dementia at the individual and population levels.
Second, the development of a drug that slows the progression of dementia may mean that more, not fewer, people will be experiencing the disease’s early phases at a given time. That is, people living with dementia may live longer and spend more years affected by the disease. Although such a delay would benefit those who maintained a higher level of function longer, it would also create the need for more support for larger numbers of people whose dementia was progressing more slowly than is currently typical.
Third, the committee is aware of no funded research that is exploring ways to cure or reverse dementia beyond the earliest phases. Brain pathology that is severe is understood to be permanent and irreversible, and brain pathology related to dementia is believed to precede symptoms by at least several years—perhaps more. There is not consensus among researchers that the elimination of senile plaques, as aducanumab is designed to do, will have a significant effect on the symptoms of Alzheimer’s disease. Thus, those millions of Americans who currently have moderate to severe dementia, as well as those who develop dementia in the next decade, are unlikely to benefit from medications aimed at prevention that emerge during that period.
Finally, any approved drug for dementia will be costly (Garde and Feuerstein, 2020). The expected costs for aducanumab are not clear but estimates just for the drug itself (to be marketed as Aduhelm) could be as high as $112 billion per year, not including necessary associated costs (see Chapter 7 for a detailed discussion of the cost estimates).5 Millions of aging Americans will wish to receive aducanumab or any other new drug. At the population level, the cost of such a drug would represent a substantial addition to Medicare and other insurance programs. Moreover, the growing population of older people would still require medical and social support for other conditions apart from dementia, and would not benefit if funding for those needs were reduced.
These realities highlight the continuing need for dementia-related research in the social and behavioral sciences. The disciplines that fall into this broad category make use of diverse methods and types of data, but they all share a focus on understanding human and social behavior, responses, and motivations, as well as institutional, social, cultural, and contextual factors that constrain or shape behavior, relationships, access to resources, and exposure to advantage or disadvantage from before conception through late life. Important domains relevant to dementia risk and living with dementia include the study of disparities in access to medical care, the socioeconomic factors that affect cognitive health, psychological study of emotional responses to disease, policies governing health care reimbursement, and many others.
Research in social and behavioral fields also is instrumental to such public health efforts as effectively disseminating information and education, supporting the adoption of innovations in care and treatment, identifying and monitoring trends, and suggesting policy remedies for disparities and health inequities. It also plays a key part in such methodological issues as
5 This estimate is based on the manufacturer’s estimate that as many as 2 million people may be currently eligible for the medication, which is expected to be priced at $56,000 per year; see Chapter 7.
interpretation of observational evidence, measurement of important exposures (e.g., racism) and outcomes (e.g., costs, quality of life), the design of clinical trials, and integration of evidence from disparate sources. Social and behavioral research can illuminate the factors that exacerbate or ameliorate dementia, and support better lives for those living with dementia and their caregivers.
Finally, dementia is a progressive and ultimately fatal illness with potentially profound impacts on the lives of all who experience it and their families. As discussed below, however, the risk of developing dementia and its impacts vary across subgroups of the population. Social and behavioral research is vital precisely because this variation is not an accident. The experiences of individuals and families are affected by factors as personal as their own financial resources, physical and emotional health, and relationships, but also by broader systemic and societal factors, including the functioning of medical and long-term care systems, the role of policy and law, the allocation of public resources, and socioeconomic factors that shape health and health care in the United States. The impacts of dementia strain all of the institutions involved, and those strains in turn increase the pressure on individuals and families. Research on the social determinants of health and related issues offers insights relevant to the disparities in both the incidence of dementia and the care and resources available.
While researchers often target average effects in populations, the impacts on individuals are just as important, and these vary markedly. One individual may have numerous advantages that both slow the development of disease and mitigate aspects of the experience, including the resources to support a healthy lifestyle, a stable family, and the financial resources to afford expert care. For another, early-life disadvantages, physically demanding work, subpar health care, a stressed family, and economic hardship may bring a very different experience. From diagnosis to the end of life, individuals with dementia and their caregivers have a wide range of experiences and outcomes. The committee sought to understand the reasons for these discrepancies and what it would take to promote wellness, well-being, and opportunities for life satisfaction for all individuals who develop dementia and their families.
The committee began its work with a broad look at the possible impacts of dementia in the United States, including data on the scope of this significant problem and evidence of disparities and inequality. The COVID-19 pandemic emerged after the project began, and we sought evidence of its impact as well.
Dementia is primarily a disease of older age. Its prevalence (defined as the percentage of individuals in the population who have a condition) increases steeply after age 60. Incidence (defined as the rate of new cases in the population) also increases steeply with age, according to recent large studies (Lucca et al., 2020; Gilsanz et al., 2019; Corrada et al., 2010). The lifetime risk of developing dementia is approximately twice as great for women as for men, in part because women live longer (Langa et al., 2017; Wolters et al., 2020; Chene et al., 2015). Black and Hispanic people are significantly more likely to develop the disease than are White people (Chen and Zissimopoulos, 2018; Plassman et al., 2007). For an important but small number of people (e.g., persons with Down syndrome), dementia can occur in midlife—in rare cases as early as the 30s but more commonly during the 40s or 50s (National Down Syndrome Society, 2021).
Dementia is expected to become more common as life expectancy increases and the largest generation in history enters the age of risk. Evidence that age-specific rates of dementia have declined in recent decades—in high-income countries—has provided a ray of hope, but the magnitude of these declining rates is modest overall, estimated at about 13 percent per decade over the past 25 years (Wolters et al., 2020). There also is no reason to assume that observed declines in age-specific incidence will continue, since one driver of the declines—rising education levels—has leveled off, and the full range of contributing causes has not been established. Moreover, the impact of any such declines will likely be more than offset by the rapidly growing numbers of people reaching the age of risk (Langa, 2015; Wolters et al., 2020). And as the U.S. population lives longer, the number of years an average person will likely live with dementia is growing (Mayeda et al., 2017b; Zissimopoulos et al., 2014; Langa, 2018).
Emerging evidence indicates that dementia does not affect all population groups in the United States equally, for complex reasons addressed throughout this report. For example, Table 1-1 shows differences by race and ethnicity reflecting 2000 census data (analyses based on the 2020 census were not yet available). These data include person-years6 affected by the disease (to account for both the different sizes of the groups themselves and differences in survival rates after onset), as well as age-adjusted incidence
6 Person-years is a measure used to calculate both the number of people in a group and the amount of time each was affected by the circumstance being studied.
rates by group. However, these data do not capture differences among subgroups in these populations, such as the many different subgroups counted as Hispanic for purposes of census data collection.
Estimates using other data also identify sharp disparities across racial/ethnic groups. For example, a population study of the epidemiology of Alzheimer’s disease indicated even starker differences, showing that both prevalence and incidence were approximately double for African American people in the study compared with those of European ancestry, although the authors note the challenges of arriving at precise estimates (Rajan et al., 2019). Research also has found that the prevalence of dementia is greatest in low-income neighborhoods and rural areas (Powell et al., 2020a; Wing et al., 2020). Research focused on locations with the highest prevalence has shown further that all groups in lower-income areas have higher rates of disease. In those areas, incidence rates are higher among Black and some Latino populations than among White people of the same age. The rates are lower among Asian American people than among their White counterparts, but there is substantial heterogeneity among Asian American groups (Dilworth-Anderson et al., 2008; Mayeda et al., 2016, 2017a; Mudrazija et al., 2020; Mehta and Yeo, 2017).
These disparities may largely reflect the legacy of systematic inequality, although contemporary conditions also influence both dementia risk and quality of life and well-being for individuals living with dementia. What have been termed the social determinants of health—such factors as education, financial stability, housing, food security, work and work conditions, social isolation, experiences of discrimination and racism, and unhealthy environments—have profound impacts on health and on experiences with the health care system (NASEM, 2016b, 2020; Plough and Christopher, 2020; Yaffe et al., 2013). These issues shaped every section of this report.
TABLE 1-1 Disparities in the Incidence and Impact of Dementia
|Racial/Ethnic Group||Total Person-Years||Age-Adjusted Incidence Rate, per 1,000 People|
|American Indian/Alaska Native||41,182||22.18|
SOURCE: Adapted from Mayeda et al. (2016).
After the committee began its work, COVID-19 began to spread in the United States, and it quickly became apparent that older adults, particularly those living in residential settings, were among the hardest hit (Powell et al., 2020b). The infection spread at lightning speed through many nursing homes and assisted living facilities. By August 2020, it was estimated that 35 to 40 percent of all those who had died from COVID-19 in the United States were residents of nursing homes (Severns, 2020; Chidabaram, 2020; Chidabaram and Garfield, 2021; Chidabaram et al., 2020a; Bernstein, 2020; Soucheray, 2020; Powell et al., 2020b). People living with dementia constitute almost one-half of nursing home residents (Harris-Kojetin et al., 2019). Because of the shocking rate of illness and death in nursing homes, they became the focus of numerous interventions, including heightened testing of both staff and residents, drastic restrictions on visiting, and early access to vaccines when they became available. Significant reductions in the rate of morbidity and mortality followed. The most recent estimate available for this report was that more than 130,000 fatalities, among nearly 600,000 total U.S. fatalities, were nursing home residents (Centers for Medicare & Medicaid Services, 2021).
Policy makers and the operators of care facilities were slow to recognize and act on the threat to vulnerable residents and especially those living with dementia; for example, many facilities did not immediately effectively isolate COVID patients (Jewett, 2020). Facilities and their staffs were also coping with many challenges: stress and illness among staff members; lack of access to COVID testing; staffing shortages; hospitals sending COVID-positive patients to nursing homes to make room for new admissions; the challenge and expense of instituting virus protection measures, especially dire shortages of personal protective equipment and egregious cost increases; and the difficulties of caring safely for residents who contracted the virus. Facilities serving traditionally disadvantaged populations, including low-income residents and members of racial/ethnic subgroups, were particularly hard hit (Chidabaram et al., 2020b). The rate of COVID in any residential setting generally reflected the rate of COVID in the surrounding community, but at least one study suggests that mortality rates were highest in facilities serving the largest percentages of non-White residents (Altman, 2020; Gorges and Konetzka, 2020, 2021).
In addition to the risk of serious illness and death, the virus posed challenges for persons living with dementia, regardless of whether they resided in care facilities, including social isolation and loss of access to vital resources, overcrowded and intergenerational households, shortages of care options, and risks to their care partners, to name but a few. Many communities that had active adult day programs, arts activities, multigenerational community
gardens, and other opportunities for social engagement closed these programs until they could be operated safely. Guidance for protecting residents unfortunately increased isolation. For example, a nationwide survey of nursing home residents conducted in summer 2020 found that only 13 percent of residents were eating meals in the dining room, compared with 69 percent before COVID restrictions began (Montgomery et al., 2020).
While researchers are just beginning to explore these issues, it is clear that for a person living with dementia, the loss of regular community or church activities; the inability to see health care providers in person; the demands of using technologies such as Zoom to communicate with providers, caregivers, or family and friends; and the disorienting nature of communication with people whose faces are covered by masks can be devastating. COVID produced exceptional stress for family caregivers as well. Not being able to visit loved ones in nursing homes, especially as rates of disease and death rose across the country, was extraordinarily painful. One distressed daughter described the isolation of a nursing home without visitors as “a slow killer” (Healy et al., 2020). Many families withdrew loved ones from nursing homes or declined admission, choosing instead to provide advanced care at home, hoping to decrease the risk of exposure to COVID (Lin, 2021).
These problems were compounded by the disparate impact of the virus. Although rates varied over time and across regions, Black, Hispanic, American Indian, and Asian people in the United States had disproportionately high rates of infection, hospitalization, and death compared with White people (Rubin-Miller et al., 2020; Manson and Buchwald, 2021). Social and economic inequities in the rates of infection were exacerbated by disparities in access to care (Grabowski and Mor, 2020).
In short, the pandemic exposed profound deficiencies in the care and support available in the United States for people living with dementia and their caregivers. Nevertheless, the pandemic also presented an opportunity to systematically examine an infrastructure that is not only vulnerable to disaster but also inadequate in ordinary times. This report, which outlines a 10-year research agenda for reducing adverse impacts of Alzheimer’s disease and other dementias and promoting the well-being of people living with dementia, was conceived long before the pandemic began. As the report goes to press, while the ultimate impact of COVID-19 is not yet known, the pandemic clearly has only heightened the urgency of the report’s purpose.
To carry out this decadal study of the impact of Alzheimer’s disease and related dementias, the committee followed the approach established in previous decadal studies by (1) assessing the needs of the communities the study
was intended to benefit, and (2) surveying the landscape of potentially relevant research for ideas with the greatest promise for advancing the objective of mitigating the impact of dementias on all of the constituencies they affect.
As with other decadal studies, the committee was aware that systematically uncovering every potentially valuable research direction would be impossible. Our criteria for identifying candidate research directions were straightforward. We looked for
- problems that are both common and serious for people living with dementia and their caregivers and can be addressed through research in the social and behavioral sciences;
- gaps in the existing research that signal opportunities for meaningful developments in interventions, policies, dementia prevention, or promotion of the well-being of people with dementia and their loved ones; and
- reason to believe those gaps could be filled within a decade using data and methods that are currently or could become available.
A decadal study of necessity reviews a wide landscape, but even within the above parameters, we could not address every relevant topic. Throughout the report we note specific areas we were unable to examine in sufficient depth to support clear research directions, but one key area deserves mention here. The health care system and the entities that provide direct care to people living with dementia (both in their homes and in residential facilities) employ millions of people, including employees ranging from highly trained medical specialists and other clinicians to the individuals who provide assistance with bathing and toileting. The United States is facing moderate to severe shortages of most categories of workers needed to care for people living with dementia, and these shortages are growing. While we recognized the critical importance of a sufficiently supplied and adequately prepared workforce in reducing the impact of dementia, we also appreciated the complexity of the issues involved. Valuable research directions would be based on understanding such issues as the nuances of workforce recruitment, training, and retention related to dementia care; broad societal factors that affect labor supply and demand; benefit structures; and immigration policies. Although a responsible examination of these issues was beyond the scope of this study, we wish to underscore their importance. Appendix B provides a brief review of these issues and the related research recommendations of the 2017 National Research Summit on Dementia Care.
The committee members brought to this study a significant body of expertise, as well as in many cases personal experiences with family members and friends who either had dementia or cared for loved ones who did. We were determined to learn all we could about the experiences of people living with dementia and those who care for people at all stages of these diseases. An advisory panel made up of individuals living with dementia and having experience as caregivers was appointed to assist in this effort; they are listed in Box 1-3 (biographical sketches of the members appear in Appendix A). Members of the advisory panel spent countless hours with us, contributing to our meetings, participating in conference calls, and assisting us in an effort to solicit perspectives from a much broader population.
The advisory panel also prepared a paper summarizing the ideas they thought were most important for the committee to understand, titled “A Summary of Commentaries Submitted by Those Living with Dementia and Care Partners” (Huling Hummel et al., 2020). This paper includes insights gained from a public call for comments from people living with dementia and caregivers about their experiences and the challenges they face, as well as the panel members’ own insights. These perspectives were very valuable as the committee developed this report, particularly Chapters 3, 4, and 5. We have included perspectives shared by advisory panel members and others throughout the report to highlight the impact of the issues discussed on families’ lives. We are indebted to the entire advisory panel for all of their contributions.
The public call for commentaries yielded 17 written responses from persons living with dementia and caregivers, as well as three responses delivered orally. We also sought input through committee members’ participation in town halls and professional meetings at which they described the project and solicited input, and through a call for white papers that was issued in fall 2019. We received 12 white papers in total and reviewed
each carefully. We also invited public comment through the project website and a series of e-blasts. Four public workshops held in conjunction with committee meetings allowed us to hear presentations both from persons who have lived with dementia and from traditional academic experts, and to engage in discussions with them and other participants. These workshops addressed
- Quality of Life for Individuals with Dementia: Preventing Elder Abuse and Fostering Living Well After a Dementia Diagnosis;7
- Nursing Home, Hospice, and Palliative Care for Individuals with Later-Stage Dementia: Making Health Systems More Responsive to Dementia;8
- Challenging Questions About Epidemiology, Care, and Caregiving for People with Alzheimer’s Disease and Related Dementias and Their Families;9 and
- ADRD Experience and Caregiving, Epidemiology, and Models of Care.10
Finally, the committee commissioned six papers to delve more deeply into key topics:11
- Bennett, D. (2020). Commissioned Paper on Defining Different Types of Dementia;
- Bynum, J.P.W, and Langa, K. (2020). Prevalence Measurement for Alzheimer’s Disease and Dementia: Current Status and Future Prospects;
- Gaugler, J., Jutkowitz, E., and Gitlin, L.N. (2020). Non-Pharmacological Interventions for Persons Living with Alzheimer’s Disease: Decadal Review and Recommendations;
11 All commissioned papers are available on the study website at https://www.nationalacademies.org/event/10-17-2019/meeting-2-decadal-survey-of-behavioral-and-social-scienceresearch-on-alzheimers-disease-and-alzheimers-disease-related-dementias.
- Gitlin, L.N., Jutkowitz, E., and Gaugler, J.E. (2020). Dementia Caregiver Intervention Research Now and into the Future: Review and Recommendations;
- Lin, P.J. (2020). Commissioned Paper on AD/ADRD Health Economics and Public Policy; and
- Quiñones, A.R., Kaye, J., Allore, H.G., Thielke, S., and Botoseneanu, A. (2020). Sociocultural Aspects and Determinants of Care for Alzheimer’s Disease and Related Dementias (ADRD) Among Minority Ethnic Populations.
We also reviewed research literature related to each of the domains we identified as key to the lived experience of dementia. Several other National Academies’ committees have addressed related topics, and we relied on their conclusions where they were relevant; see Box 1-4.
Several themes from social and behavioral research shaped the committee’s work and run through this report. These include the critical importance of context and development across the life course; the intertwined impacts of dementia on those who have the disease and their caregivers; and ethical issues, such as the balance between safety and autonomy.
Context, from the immediate influences that shape the life of an individual to the larger societal influences that affect health and well-being at a population level, is increasingly recognized as essential to understanding many phenomena. It was particularly important for understanding the stark disparities in both the incidence of dementia and access to high-quality care discussed above. The importance of context to human development was notably articulated in the 1970s by psychologist Urie Bronfenbrenner, who proposed an ecological perspective for understanding the interactions among biological and social influences (Bronfenbrenner, 1977, 1994; for a detailed discussion of research on the influences of environment and context, see, e.g., NASEM, 2019b, 2019c). Researchers in numerous disciplines have built on this idea, particularly in the area of fetal and early-childhood development. They have identified linkages between characteristics of the individual’s environment and neurodevelopment, and even the expression of genes later in life. Researchers have also traced the negative impacts of numerous environmental influences on development in the most vulnerable and disadvantaged populations of children, and have pointed to cross-generational effects that serve to perpetuate disadvantage (NASEM, 2019b).
Similarly, in studying dementia and its impacts, it is critical to recognize that every individual affected by dementia is embedded in the context of home, family, community, and society. Factors ranging from characteristics
of neighborhoods, to the legacy of racial discrimination in local housing policies, to the long-standing lingering effects of residential segregation, to federal policies regarding Medicare or the clean-up of toxic pollutants are relevant to dementia risk and progression. These factors interact in ways that can amplify both positive and negative effects on the health and well-being of families and individuals.
Like many contemporary researchers, we also considered a life-course approach in examining cognitive function and dementia in late life (Alwin et al., 2016; Glymour and Manly, 2008; Livingston et al., 2020; Richards and Deary, 2005; Whalley et al., 2006; Zhang et al., 2016). The life-course framework—a way of examining change across the life span—is related to the ecological approach and has also been applied in many contexts (Alwin, 2012).12 Taking a life-course perspective led the committee to look not only
at the experiences that begin when symptoms appear or when medical care is required, but also at the factors that may eliminate, ameliorate, or exacerbate risk beginning long before the onset of disease.
With the above ideas in mind, the committee looked across the potential impacts of dementia and identified those areas in which we saw the greatest potential leverage for improving outcomes. Accordingly, the report is structured around these primary areas:
- Risk and preventive factors for dementia and how they relate to the social determinants of health—the social and economic conditions that affect health care and health outcomes (Chapter 2).
- The personal experience of living with dementia and the issues associated with diagnosis, care, and treatment (Chapter 3).
- The experiences of family caregivers and resources available to them (Chapter 4).
- How characteristics of communities affect dementia risk and quality of life for people living with dementia and their families, and the broad social forces that shape communities (Chapter 5).
- The health care system and the institutions that provide residential long-term care and hospice and palliative care (Chapter 6).
- The economic costs of dementia to individuals and to society (Chapter 7).
Each of these chapters offers directions for research in the coming decade. Chapter 8 reviews methodological issues that affect research across these areas and suggests pathways for strengthening the evidence base to support progress in reducing the negative impacts of dementia. Chapter 9 summarizes the committee’s recommended research agenda.
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