Kelsey E. Woods, Christina M. Danko, and Andrea Chronis-Tuscano
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by developmentally inappropriate levels of hyperactivity, impulsivity, and/or inattention. ADHD is chronic, may persist into adulthood, and is associated with impairment in social and academic/work domains across the lifespan. Children and adolescents with ADHD often present with executive function deficits and emotion dysregulation, and these deficits may increase impairment and risk for co-occurring disorders. The etiology of ADHD is not yet understood, though research suggests that biological and environmental factors (e.g., family, community) contribute to its development and course. It should be noted that ADHD commonly co-occurs with additional psychiatric disorders, such as oppositional defiant disorder (ODD), conduct disorder (CD), and major depressive disorder.
Evidence-based assessment of ADHD requires information from multiple informants using multiple assessment methods to determine the presence of ADHD symptoms across settings and any co-occurring disorders. The evidence-based treatment options for ADHD are manifold. Pharmacotherapy for ADHD is common, although numerous behavioral interventions are also effective. Stimulant medications are commonly prescribed and are typically effective in ameliorating core ADHD symptoms. There is also evidence that the nonstimulant medication atomoxetine substantially decreases the symptoms of ADHD. Importantly, medication therapy works to reduce symptoms but typically does not alleviate the impairments associated with the disorder. Combined medication and behavioral interventions are more likely to reduce impairments and normalize behavior.
Jack Kuhns and Dayna R. Touron
The study of aging and cognitive skill learning is concerned with age-related changes and differences in how we gather, store, and use information and abilities. As life expectancy continues to rise, resulting in greater numbers and proportions of older individuals in the population, understanding the development and retention of skills across the lifespan is increasingly important. Older adults’ task performance in cognitive skill learning is often equal to that of young adults, albeit not as efficient, where older adults often require more time to complete training. Investigations of age differences in fundamental cognitive processes of attention, memory, or executive functioning generally reveal declines in older adults. These are related to a slowing of cognitive processing. Slowing in cognitive processing results in longer time necessary to complete tasks which can interfere with the fidelity of older adults’ cognitive processes in time-limited scenarios. Despite this, older adults maintain comparable rates of learning with young adults, albeit with some reduced efficiency in more complex tasks. The effectiveness of older adults’ learning is also impacted by a lesser tendency to recognize and adopt efficient learning strategies, as well as less flexibility in strategy use relative to younger adults. In learning tasks that involve a transition from using a complex initial strategy to relying on memory retrieval, older adults show a volitional avoidance of memory that is related to lower memory confidence and an impoverished mental model of the task. Declines in learning are not entirely problematic from a functional perspective, however, as older adults can often rely upon their extensive knowledge to compensate for certain deficiencies, particularly in everyday tasks. Indeed, domains where older adults have maintained expertise are somewhat insulated from other age-related declines.
Victoria I. Michalowski, Denis Gerstorf, and Christiane A. Hoppmann
Aging does not occur in isolation, but often involves significant others such as spouses. Whether such dyadic associations involve gains or losses depends on a myriad of factors, including the time frame under consideration. What is beneficial in the short term may not be so in the long term, and vice versa. Similarly, what is beneficial for one partner may be costly for the other, or the couple unit over time. Daily dynamics between partners involving emotion processes, health behaviors, and collaborative cognition may accumulate over years to affect the longer-term physical and mental health outcomes of either partner or both partners across adulthood and into old age. Future research should move beyond an individual-focused approach to aging and consider the importance of and interactions among multiple time scales to better understand how, when, and why older spouses shape each other’s aging trajectories, both for better and for worse.
Allison R. Heid and Steven H. Zarit
Individuals are living longer than they ever have before with average life expectancy at birth estimated at 79 years of age in the United States. A greater proportion of individuals are living to advanced ages of 85 or more and the ratio of individuals 65 and over to individuals of younger age groups is shrinking. Disparities in life expectancy across genders and races are pronounced. Financial challenges of sustaining the older population are substantial in most developed and many developing countries. In the United States in particular, employer-based pension programs are diminishing. Furthermore, Social Security will begin taking in less money than it pays out as early as 2023, and the debate over its future in part entails discussions of equitable distribution of resources for the young in need and the old. Living longer is associated with a greater number of chronic health conditions—over two-thirds of Medicare beneficiaries in the United States have two or more chronic health conditions that require complex self-management regimes partnered with informal and formal care services from family caregivers and institutional long-term services and supports. Caregiver burden and stress is high as are quality care deficiencies in residential long-term care settings. The balance of honoring individuals’ autonomous wishes and providing person-centered care that also addresses the practicalities of safety is an ever-present quandary. Furthermore, complex decisions regarding end-of-life care and treatments plague the medical and social realms, as more money is spent at the end of life than at any other point and individuals’ wishes for less invasive treatment are often not accommodated. Yet, despite these challenges of later life, a large percentage of older individuals are giving financial support, time, and energy to younger generations, who are increasingly strained by economic hardship, the pressures on dual earner parents, and the problems faced by single parenthood. Older individuals’ engagement in society and the help they provide others runs counter to stereotypes that render them helpless and lonely. Overall, the ethical challenges faced by society due to the aging of the population are considerable. Difficult decisions that must be addressed include the sustainability of programs, resources, and social justice in care, as well as how to marshal the resources, talents, and wisdom that older people provide.
Gizem Hülür and Elisa Weber
Lifespan development is embedded in multiple social systems and social relationships. Lifespan developmental and relationship researchers study individual codevelopment in various dyadic social relationships, such as dyads of parents and children or romantic partners. Dyadic data refers to types of data for which observations from both members of a dyad are available. The analysis of dyadic data requires the use of appropriate data-analytic methods that account for such interdependencies. The standard actor-partner interdependence model, the dyadic growth curve model, and the dyadic dual change score model can be used to analyze data from dyads. These models allow examination of questions related to dyadic associations such as whether individual differences in an outcome can be predicted by one’s own (actor effects) and the other dyad member’s (partner effects) level in another variable, correlated change between dyad members, and cross-lagged dyadic associations, that is, whether one dyad member’s change can be predicted by the previous levels of the other dyad member. The choice of a specific model should be guided by theoretical and conceptual considerations as well as by features of the data, such as the type of dyad, the number and spacing of observations, or distributional properties of variables.
Jonathan S. Gooblar and Sherry A. Beaudreau
Anxiety disorders are among the most prevalent and understudied mental health problems in late life. Specific phobia, social anxiety disorder, and generalized anxiety disorder are the most prevalent anxiety disorders in older adults among the 11 disorders identified by the Diagnostic and Statistical Manual of Mental Disorders (fifth edition). Anxiety disorders lead to significant functional burdens and interface with physical health problems and cognitive impairment, concerns frequently experienced in adults over age 65. Additional contextual factors should be considered when assessing and treating late-life anxiety, including the effects of polypharmacy, other mental health conditions, role changes, and societal attitudes toward aging. The relationship between anxiety and physical health problems in older adults can be causal or contextual, and can involve poorer estimates of subjective health and lower ratings of functioning. These factors present unique challenges to the detection, conceptualization, and treatment of late-life anxiety, including the tendency for older adults to focus on somatic symptoms and the potential for long-term behaviors that can mask distress such as substance use. Researchers are increasingly incorporating a gerodiversity framework to understand the contributions of cultural, individual, and other group differences that may affect the presentation of anxiety symptoms and disorders. Older adults in general are less likely to be treated for anxiety disorders, and intersecting individual and group differences likely further affect how anxiety disorders are perceived by healthcare providers. Cognitive behavioral therapy and its variants have the most empirical support for treatment. Newer evidence lends support to acceptance and commitment therapy and problem-solving therapy, which tend to address some of the contextual factors that may be important in treatment.
Ye In (Jane) Hwang, Kitty-Rose Foley, Samuel Arnold, and Julian Trollor
Autism spectrum disorder (ASD), or autism, is a neurodevelopmental disorder that is typically recognized and diagnosed in childhood. There is no established biological marker for autism; rather, the diagnosis is made based on observation of behavioral traits, including (a) persistent deficits in social interaction and communication, and (b) restricted, repetitive patterns of behavior, interests, or activities. Because autism is a spectrum disorder, autistic individuals are a highly heterogeneous group and differ widely in the presentation and severity of their symptoms. The established prevalence of ASD is approximately 1% of the population.
Information about autism in adulthood is limited; most of the literature examines childhood and adolescence. While the term “later life” has traditionally been associated with those over the age of 65, a dire lack of understanding exists for those on the autism spectrum beyond early adulthood.
Individuals remain on the spectrum into later life, though some mild improvements in symptoms are observed over time. Autistic adults experience high levels of physical and mental health comorbidities. Rates of participation in employment and education are also lower than that of the general population. Quality of life is reportedly poorer for autistic adults than for nonautistic peers, though this is not affected by age. More robust studies of the health, well-being, and needs of autistic adults are needed, especially qualitative investigations of adulthood and aging and longitudinal studies of development over the lifespan.
Anne Josephine Dutt, Hans-Werner Wahl, and Manfred Diehl
The term Awareness of Aging (AoA) incorporates all aspects of individuals’ perceptions, behavioral experiences, and subjective interpretations related to their process of growing older. In this regard, AoA goes beyond objective descriptions of the aging process, such as calendar age or biological age. Commonly used AoA constructs referring to the ongoing experience of the aging process encompass concepts such as subjective age, attitudes toward one’s own aging, self-perceptions of aging, and awareness of age-related change. AoA also incorporates elements that are more pre-conscious in nature, such as age stereotypes and culturally held notions about the aging process. Despite their theoretically broad common foundation, AoA constructs differ according to their specific frames of reference, such as whether and how they take into account the multidimensionality and multi-directionality of development. Examining the existing body of empirical work identifies several antecedents of AoA, such as sociodemographic “background” variables, physical health and physical functioning, cognition, psychological well-being and mental health, psychological variables (e.g., personality, anxiety), and life events. In general, more positive manifestations on these variables are accompanied by a more positive perception and evaluation of the aging process. Moreover, AoA is longitudinally linked to important developmental outcomes, such as health, cognition, subjective well-being, and mortality. Overall, the study of AoA has developed as a promising area of psychological aging research that has grown in its conceptual and empirical rigor during recent years.
Lizbeth Benson and Nilam Ram
In ecological sciences, biodiversity is the dispersion of organisms across species and is used to describe the complexity of systems where species interact with each other and the environment. Some argue that biodiversity is important to cultivate and maintain because higher levels are indicative of health and resilience of the ecosystem. Because each species performs functional roles, more diverse ecosystems have greater capability to respond, maintain function, resist damage, and recover quickly from perturbations or disruptions. In the behavioral sciences, diversity-type constructs and metrics are being defined and operationalized across a variety of functional domains (socioemotional, self, cognitive, activities and environment, stress, and biological). Emodiversity, for instance, is the dispersion of an individual’s emotion experiences across emotion types (e.g., happy, anger, sad). Although not always explicitly labeled as such, many core propositions in lifespan developmental theory—such as differentiation, dedifferentiation, and integration—imply intraindividual change in diversity and/or interindividual differences in diversity. For example, socioemotional theories of aging suggest that as individuals get older, they increasingly self-select into more positive valence and low arousal emotion inducing experiences, which might suggest that diversity in positive and low arousal emotion experiences increases with age. When conceptualizing and studying diversity, important considerations include that diversity (a) provides a holistic representation of human systems, (b) differs in direction, interpretation, and linkages to other constructs such as health (c) exists at multiple scales, (d) is context-specific, and (e) is flexible to many study designs and data types. Additionally, there are also a variety of methodological considerations in study of diversity-type constructs including nuances pertaining theory-driven or data-driven approaches to choosing a metric. The relevance of diversity to a broad range of phenomena and the utility of biodiversity metrics for quantifying dispersion across categories in multivariate and/or repeated measures data suggests further use of biodiversity conceptualizations and methods in studies of lifespan development.
Thomas M. Hess, Erica L. O'Brien, and Claire M. Growney
Blood pressure is a frequently used measure in studies of adult development and aging, serving as a biomarker for health, physiological reactivity, and task engagement. Importantly, it has helped elucidate the influence of cardiovascular health on behavioral aspects of the aging process, with research demonstrating the negative effect of chronic high blood pressure on various aspects of cognitive functioning in later life. An important implication of such research is that much of what is considered part and parcel of getting older may actually be reflective of changes in health as opposed to normative aging processes. Research has also demonstrated that situational spikes in blood pressure to emotional stressors (i.e., reactivity) also have implications for health in later life. Although research is still somewhat limited, individual differences in personal traits and living circumstances have been found to moderate the strength of reactive responses, providing promise for the identification of factors that might ameliorate the effects of age-related changes in physiology that lead to normative increases in reactivity. Finally, blood pressure has also been successfully used to assess engagement levels. In this context, recent work on aging has focused on the utility of blood pressure as a reliable indicator of both (a) the costs associated with cognitive engagement and (b) the extent to which variation in these costs might predict both between-individual and age-related normative variation in participation in cognitively demanding—but potentially beneficial—activities. This chapter elaborates on these three approaches and summarizes major research findings along with methodological and interpretational issues.
M. Lindsey Jacobs and Patricia M. Bamonti
The field of geropsychology has grown worldwide since the 1990s, particularly in the United States. In the early 21st century, professional geropsychology was recognized by the American Psychological Association as a clinical specialty. Despite this growth, there is a shortage of practicing psychologists proficient in geropsychology to meet the mental health needs of older adults. Moreover, the need for psychologists with geriatric training is continuing to grow as healthcare increasingly shifts to integrated care, creating a demand for psychologists in clinical settings such as nursing homes, hospice and palliative care, primary care, and home-based primary care. The widening gap between supply and demand requires strategic recruitment and educational initiatives to grow the number of providers with competency in working with older adults. Recruitment strategies emphasize increasing supply by “priming the pipeline” through the creation of early exposure opportunities at the secondary, undergraduate, and graduate school level, strategic recruitment of underrepresented students, and expanding financial incentives for practice.
Training and education in geropsychology have advanced considerably. The Pikes Peak Model for Professional Geropsychology Training provides the structure to gauge competency development. A framework for obtaining competency at the generalist, generalist with proficiency, and specialist levels has been created. In future years, there will be greater demand for post-licensure training in geropsychology, and geropsychologists will increasingly function as clinical educators. Technological advances will play a vital role in disseminating geropsychology education to generalist providers and related disciplines interested in gaining geropsychology exposure.
Michael J. Valenzuela
Cognitive reserve refers to the many ways that neural, cognitive, and psychosocial processes can adapt and change in response to brain aging, damage, or disease, with the overarching effect of preserving cognitive function. Cognitive reserve therefore helps to explain why cognitive abilities in late life vary as dramatically as they do, and why some individuals are brittle to degenerative pathology and others exceptionally resilient. Historically, the term has evolved and at times suffered from vague, circular, and even competing notions. Fortunately, a recent broad consensus process has developed working definitions that resolve many of these issues, and here the evidence is presented in the form of a suggested Framework: Contributors to cognitive reserve, which include environmental exposures that demand new learning and intellectual challenge, genetic factors that remain largely unknown, and putative G × E interactions; mechanisms of cognitive reserve that can be studied at the biological, cognitive, or psychosocial level, with a common theme of plasticity, flexibility, and compensability; and the clinical outcome of (enriched) cognitive reserve that can be summarized as a compression of cognitive morbidity, a relative protection from incident dementia but increased rate of progression and mortality after diagnosis. Cognitive reserve therefore has great potential to address the global challenge of aging societies, yet for this potential to be realized a renewed scientific, clinical, and societal focus will be required.
Lydia K. Manning, Lauren M. Bouchard, and James L. Flanagan
There is a great deal of concern about the increasing number of older adults who suffer from chronic disease. These conditions result in persistent health consequences and have an ongoing and long-term negative impact on people and their quality of life. Furthermore, the probability that a person will experience the onset of multiple chronic conditions, known as comorbidities, increases with age. Despite the prevalence of comorbidity in later life, scant research exists regarding specific patterns of disease and the co-occurrence and complex interactions of the chronic conditions most closely associated with aging. It is important to review the body of literature on comorbidities associated with physical and psychiatric syndromes in later life to gain an overview of some of the most commonly seen disorders in older adults: hypertension, diabetes, cardiovascular disease, chronic obstructive pulmonary disease, arthritis, depression, and dementia. Specific patterns of disease and the co-occurrence and complex interactions of chronic conditions in later life are explored. In conclusion, we consider the need for a more informed understanding of comorbidity, as well as a related plan for addressing it.
Alison Chasteen, Maria Iankilevitch, Jordana Schiralli, and Veronica Bergstrom
In 2016, Statistics Canada released the results of the most recent census. For the first time ever, the proportion of Canadians aged 65-plus years surpassed the proportion aged 15 and under. The increase in the proportion of older adults was viewed as further evidence of the faster rate of aging of Canada’s population. Such demographic shifts are not unique to Canada; many industrialized nations around the world are experiencing similar changes in their populations. Increases in the older adult population in many countries might produce beneficial outcomes by increasing the potential for intergenerational contact and exposure to exemplars of successful aging. Such positive intergenerational contact could counter prevailing age stereotypes and improve intergenerational relations. On the other hand, such increases in the number of older adults could be viewed as a strain and potential threat to resources shared with younger age groups. The possibility of increased intergenerational conflict makes it more important than ever before to understand how older adults are stereotyped, how those stereotypes can produce different kinds of biased behavior toward them, and what the impact of those stereotypes are on older adults themselves.
Social-cognitive age representations are complex and multifaceted. A common stereotype applied to older people is one of warmth but incompetence, often resulting in paternalistic prejudice toward them. However, such benevolent prejudice, characterized by warm overtones, can change to hostile bias if older adults are perceived to violate prescriptive norms about age-appropriate behavior. In addition to coping with age prejudice, older adults also have to deal with the deleterious effects of negative age stereotypes on their day-to-day function. Exposure to negative aging stereotypes can worsen older adults’ cognitive performance in a number of contexts. As well, age stereotypes can be incorporated into older adults’ own views of aging, also leading to poorer outcomes for them in a variety of domains. A number of interventions to counteract the effects of negative aging stereotypes appear promising, but more work remains to be done to reduce the impact of negative aging stereotypes on daily function in later life.
Ideas regarding what it means to age well date back centuries. Gerontological scholarship includes countless conceptual, theoretical, and empirical contributions to how to make sense of these ideas. The construct of successful aging is therefore one of the most debated operationalizations of what it means to age well. Empirical research on successful aging taps into either understandings of successful aging or the strategies that people use to age well. The very essence of the construct of successful aging is, however, sociocultural. This is why this chapter proposes that exploring the cultural values that underpin the understandings of successful aging that inform this scholarship is a theoretically profuse approach to making sense of the controversy that surrounds this construct.
Two decades ago, a culture-relevant framework for the study of understandings of successful aging was formulated to address the disregard for cultural values that lie at the very core of this controversy. This framework proposes that there is congruence between the value orientations that people prefer and the understandings of successful aging that they hold, and that if we are to make sense of this congruence, we need to acknowledge that the foundations of value orientations (i.e., political, economic, and religious systems) shape what we deem to be necessary for aging well. From this it follows that there are bound to be more understandings of successful aging than what the scholarship in this area tends to acknowledge. After all, gerontological scholarship relies most heavily on contributions made on the basis of data from highly industrialized societies in the part of the world referred to as “the West.” In other words, gerontological scholarship on successful aging is extremely ethnocentric in its take on this construct, since only a handful of cultural understandings of what it means to age well are regarded as the norm. A failure to acknowledge this very fact leads gerontologists to disregard or downplay (often inadvertently) understandings of what it means to age well that do not resonate well with their own value paradigms or to impose (sometimes unintentionally) the Western template on findings about successful aging that do not rhyme well with what this scholarship assumes to be a given (i.e., a future, activity, independence, and mastering of nature orientation to what aging well means).
Li Chu, Yang Fang, Vivian Hiu-Ling Tsang, and Helene H. Fung
Cognitive processing of social and nonsocial information changes with age. These processes range from the ones that serve “mere” cognitive functions, such as recall strategies and reasoning, to those that serve functions that pertain to self-regulation and relating to others. However, aging and the development of social cognition unfold in different cultural contexts, which may assume distinct social norms and values. Thus, the resulting age-related differences in cognitive and social cognitive processes may differ across cultures. On the one hand, biological aging could render age-related differences in social cognition universal; on the other hand, culture may play a role in shaping some age-related differences. Indeed, many aspects of cognition and social cognition showed different age and culture interactions, and this makes the study of these phenomena more complex. Future aging research on social cognition should take cultural influences into consideration.
Michael Cole and Martin Packer
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Psychology. Please check back later for the full article.
There is a growing appreciation of the importance of understanding the role of culture in children’s psychological development (also called human ontogenesis). In particular, the texts of Lev Vygotsky contributed greatly to a “cultural psychology” in which the study of culture and development is seen as central. At the same time, cross-cultural research in psychology has paid growing attention to developmental issues. Although there continues to be much debate over how to define culture, it is generally agreed that different human social groups have distinct cultures. It is common to assume, in addition, that cultural differences lead to differences in the trajectories of children’s development. This is true, but it is also the case that culture is a universal requirement for development. The interdependence of human communities—which probably had its origins in collaborative hunting and cooperative childrearing—seems to have placed demands on children’s development, selecting for a sensitivity to norms and to other people’s goals and intentions. Every child is born into a family and community with a language, customs, and conventions, and in which people have institutional rights and responsibilities. These define universal requisites of human psychological development: These include the acquisition of language, the development of a social identity, the understanding of community obligations, and the ability to contribute to the reproduction of the community. An open question today is the character of the capacities that children bring to these developmental tasks: the apparently species-unique ability that has made possible vast “cumulative” societies.
Shevaun D. Neupert and Jennifer A. Bellingtier
Daily diary designs allow researchers to examine processes that change together on a daily basis, often in a naturalistic setting. By studying within-person covariation between daily processes, one can more precisely establish the short-term effects and temporal ordering of concrete daily experiences. Additionally, the daily diary design reduces retrospective recall bias because participants are asked to recall events that occurred over the previous 24-hour period as opposed to a week or even a year. Therefore, a more accurate picture of individuals’ daily lives can be captured with this design. When conclusions are drawn between people about the relationship between the predictors and outcomes, the covariation that occurs within people through time is lost. In a within-person design, conclusions can be made about the simultaneous effects of within-person covariation as well as between-person differences. This is especially important when many interindividual differences (e.g., traits) may exist in within-person relationships (e.g., states).
Daily diary research can take many forms. Diary research can be conducted with printed paper questionnaires, divided into daily booklets where participants mail back each daily booklet at the end of the day or entire study period. Previous studies have called participants on the telephone to respond to interview questions each day for a series of consecutive days, allowing for quantitative as well as qualitative data collection. Online surveys that can be completed on a computer or mobile device allow the researcher to know the specific day and time that the survey was completed while minimizing direct involvement with the collection of each daily survey. There are many opportunities for lifespan developmental researchers to adopt daily diary designs across a variety of implementation platforms to address questions of important daily processes. The benefits and drawbacks of each method along with suggestions for future work are discussed, noting issues of particular importance for aging and lifespan development.
Shellie-Anne T. Levy and Glenn E. Smith
Dementia, also now known as major neurocognitive disorder, is a syndrome involving decline in two or more areas of cognitive function sufficient to disrupt a person’s daily function. Mild cognitive impairment (MCI), also known as minor neurocognitive disorder, represents a syndrome on the continuum of cognitive decline that is a stage prior to development of functional deficits. It involves decline in one or more areas of cognitive function with independence in instrumental activities of daily living, even though they may require greater effort or compensation on the part of the individual. Neuropsychological assessment of cognition and behavior provides the most powerful biomarkers for MCI and dementia syndromes associated with neurodegenerative diseases. Discrete cognitive and behavioral patterns that occur early in the course of cognitive decline aids in differential clinical diagnosis. Additionally, all diagnostic schemes for dementia syndromes include criteria that require the appraisal of functional status, which tests an individual’s capacity to engage in decision making and carry out activities of daily living independently. Methods for assessing functional status have historically had poor reliability and validity. Nevertheless, in a clinical setting, neuropsychologists rely on a combination of self-report, collateral informants, caregiver questionnaires, and objective performance-based measures to better assess functional status. Revisions to clinical criteria for dementia reflect the adoption of new research diagnostic criteria for neurodegenerative diseases, largely driven by the National Institutes of Aging (NIA) and the Alzheimer’s Association 2011 research criteria for Alzheimer’s disease (AD). The new approach differentiates the syndromic presentations common to most neurodegenerative diseases from the etiologies (AD, LBD, VaD, etc.) based on biomarkers. In the preclinical stage, biomarker abnormalities are present years before clinical symptom manifestation. In mild cognitive impairment stage, there is a report/concern for cognitive change by the patient, informant, or clinician. There is objective cognitive decline from estimated premorbid functioning and preserved independence in functional abilities. In the dementia stage, in the context of impaired functional status, there may be prominent cognitive and behavioral symptoms that may involve impairment in memory, executive function, visuospatial functioning, and language, as well as changes in personality and behavior. The most common dementias are AD, dementia with Lewy bodies (DLB), frontotemporal dementia (FTD), and vascular dementia (VaD). All can follow a trajectory of cognitive decline similar to the aforementioned stages and are associated with neuropathogenic mechanisms that may or may not be distinctive for a particular syndrome. Briefly, Alzheimer’s dementia is associated with accumulation of amyloid plaques and tau neurofibrillary tangles. Lewy body dementias (i.e., Parkinson’s disease dementia and DLB) are characterized by Lewy bodies (alpha-synuclein aggregates) and Lewy neurites in the brainstem, limbic system, and cortical regions; DLB is also associated with diffuse amyloid plaques. Frontotemporal dementia is a conglomerate of syndromes that may overlap and include behavioral variant FTD, semantic dementia, and primary progressive aphasia (PPA). FTD dementia syndromes are marked by frontotemporal lobar degeneration (FTLD) caused by pathophysiological processes involving FTLD-tau, FTLD-TDP, FTLD-FUS, or their combination, as well as beta amyloid. Lastly, vascular dementia is associated with cerebrovascular disease that can include large artery occlusions, microinfarcts, brain hemorrhages, and silent brain infarcts; comorbid AD pathology may lower the threshold for dementia conversion. There is an emerging shift in the field toward exploring prevention strategies for dementia. Given the lack of precision in our language regarding the distinction between dementia syndromes and etiologies, we can reallocate some of our efforts to preventing dementia more broadly rather than intervening on a certain pathology. Research already supports that many individuals have biomarker evidence of brain pathology without showing cognitive impairment or even sufficient levels of pathology in the brain to warrant a diagnosis without ever displaying the clinical syndrome of dementia. That said, building cognitive reserve or resilience through lifestyle and behavioral factors may slow the rate of cognitive decline and prevent the risk of a future dementia epidemic.
Jeremy B. Yorgason, Melanie S. Hill, and Mallory Millett
The study of development across the lifespan has traditionally focused on the individual. However, dyadic designs within lifespan developmental methodology allow researchers to better understand individuals in a larger context that includes various familial relationships (husbands and wives, parents and children, and caregivers and patients). Dyadic designs involve data that are not independent, and thus outcome measures from dyad members need to be modeled as correlated. Typically, non-independent outcomes are appropriately modeled using multilevel or structural equation modeling approaches. Many dyadic researchers use the actor-partner interdependence model as a basic analysis framework, while new and exciting approaches are coming forth in the literature. Dyadic designs can be extended and applied in various ways, including with intensive longitudinal data (e.g., daily diaries), grid sequence analysis, repeated measures actor/partner interdependence models, and vector field diagrams. As researchers continue to use and expand upon dyadic designs, new methods for addressing dyadic research questions will be developed.