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.
Interprofessional Training and Practice: The Need for More Engagement, Training, and Research in Geropsychology
Nancy A. Pachana and Gwen Yeo
Interdisciplinary teams consisting of a variety of health professionals working toward common patient goals have become an important innovation in clinical practice. In many parts of the world interdisciplinary teams have become part of practice, including in geriatrics. However, many gaps and the need for further empirical research and translation into practice remain. This is particularly true for the discipline of psychology, as much of the extant literature in engagement, training and practice in geriatric settings or educational settings does not include psychologists. Many advances in interprofessional teams, in acute settings in particular, do not include psychologists as part of the team. With respect to training, educating trainee health professionals, including psychologists, in interdisciplinary practice has still not become a standard part of training curricula internationally. Several excellent models of interprofessional and interdisciplinary training, including international models of interdisciplinary team competencies, have been developed. However, both the empirical testing of these models and their implementation in educational and practice settings is lacking. Within the geriatric healthcare context, the evidence base for both interprofessional care and the need for enhanced training models incorporating interprofessional skills is evolving, and further research on efficacy in evolving clinical contexts and translation into educational contexts worldwide is required. Ultimately, psychology must increase its presence within both interprofessional research and applied contexts.
Eric S. Cerino and Karen Hooker
Intraindividual variability (IIV) refers to short-term fluctuations that may be more rapid, and are often conceptualized as more reversible, than developmental change that unfolds over a longer period of time, such as years. As a feature of longitudinal data collected on micro timescales (i.e., seconds, minutes, days, or weeks), IIV can describe people, contexts, or general processes characterizing human development. In contrast to approaches that pool information across individuals and assess interindividual variability in a population (i.e., between-person variability), IIV is the focus of person-centered studies addressing how and when individuals change over time (i.e., within-person variability). Developmental psychologists interested in change and how and when it occurs, have devised research methods designed to examine intraindividual change (IIC) and interindividual differences in IIC. Dispersion, variability, inconsistency, time-structured IIV, and net IIV are distinct operationalizations of IIV that, depending on the number of measures, occasions, and time of measurement, reflect unique information about IIV in lifespan developmental domains of interest. Microlongitudinal and measurement-burst designs are two methodological approaches with intensive repeated measurement that provide a means by which various operationalizations of IIV can be accurately observed over an appropriate temporal frame to garner clearer understanding of the dynamic phenomenon under investigation. When methodological approaches are theoretically informed and the temporal frame and number of assessments align with the dynamic lifespan developmental phenomenon of interest, researchers gain greater precision in their observations of within-person variability and the extent to which these meaningful short-term fluctuations influence important domains of health and well-being. With technological advancements fueling enhanced methodologies and analytic approaches, IIV research will continue to be at the vanguard of pioneering designs for elucidating developmental change at the individual level and scaling it up to generalize to populations of interest.
Clemens Tesch-Roemer and Oliver Huxhold
Social isolation refers to the objective lack of social integration. Loneliness, in contrast, refers to the perceived lack of social integration. Loneliness has serious consequences for the well-being of aging persons. Individuals who feel lonely tend to have poorer health, less autonomy, and lower subjective well-being than individuals who do not feel lonely. Lonely individuals even tend to become more socially isolated over time. While prevalence rates of social isolation increase with advancing age, only a minority of older people suffer from severe loneliness, however. Hence, loneliness is not necessarily a consequence of growing old, but rather, depends on specific risk factors (e.g., social needs, social expectations, resources, and competencies). Interventions therefore should be focused on these risk factors (unfulfilled social needs, unmet social perceptions, and lack of resources and competencies).
Well-being is a core concept for both individuals, groups and societies. Greater understanding of trajectories of well-being in later life may contribute to the achievement and maintenance of well-being for as many as possible. This article reviews two main approaches to well-being: hedonic and eudaimonic well-being, and shows that it is not chronological age per se, but various factors related to age that underlie trajectories of well-being at older ages. Next to the role of genes, heritability and personality traits, well-being is determined to a substantial extent by external circumstances and resources (e.g., health and social relationships), and to malleable individual behaviors and beliefs (e.g., self-regulatory ability and control beliefs). Although many determinants have been identified, it remains difficult to decide which of them are most important. Moreover, the role of some determinants varies for different indicators of well-being, such as positive affect and life satisfaction. Several prominent goal- and need-based models of well-being in later life are discussed, which explicate mechanisms underlying trajectories of well-being at older ages. These are the model of Selection, Optimization, and Compensation, the Motivational Theory of Lifespan Development, Socio-emotional Selectivity Theory, Ryff’s model of Psychological Well-Being, Self-Determination Theory, and Self-Management of Well-being theory. Also, interventions based on these models are reviewed, although not all of them address older adults. It is concluded that the literature on well-being in later life is enormous, and, together with various conceptual models, offers many important insights. Still, the field would benefit from more theoretical integration, and from more attention to the development and testing of theory-based interventions. This remains a challenge for the science of well-being in later life, and could be an important contribution to the well-being of a still growing proportion of the population.
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.
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.
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.
Carolyn M. Aldwin and Ritwik Nath
Erythocyte sedimentation rate (ESR) is one of the oldest measures of inflammation. It is used extensively in clinical medicine and has shown some utility in biomedical research. It is a nonspecific inflammation assay, and although it is less sensitive than more modern measures such as C-reactive protein, it is a useful measure in chronic illnesses.
In general, ESR increases with age and appears to be a biomarker of aging in general. It predicts both cardiovascular disease (CVD) and cancer and is elevated in autoimmune disorders such as rheumatoid arthritis. Further, it predicts mortality both in the general population and in those with chronic illnesses such as CVD and cancer, independent of other indicators of illness severity.
Interestingly, ESR is not associated with anxiety or general measures of distress but is consistently associated with measures of depression and suicidal ideation. Further, the effect of depressive symptoms on mortality appears to be mediated through increases in ESR.
Studies of the relationship between stress and ESR have been less consistent, primarily because early studies were largely cross-sectional and in small samples. Studies using more modern, longitudinal analyses in larger samples may show more consistent results, especially if multilevel modeling was used that examined within-person changes in ESR in response to stress. Given that other large, longitudinal studies, such as the Baltimore Longitudinal Study on Aging, the Rotterdam Study, The Reykjavik Cohort Study, and Women’s Healthy Ageing Study have included ESR in their biomedical assays, it should be possible to analyze existing data to examine how psychosocial factors influence inflamm-aging in humans.