Cognitive epidemiology explores cognitive ability as a risk factor for various health and disease-related outcomes. To support research in this area, the Understanding America Study (UAS)-a nationally representative online probability sample-has developed and collected longitudinal assessments of multiple cognitive domains (e.g., fluid intelligence, executive function, processing speed, verbal episodic memory). These assessments have been compiled into the Cognitive Comprehensive File (CogCF), a publicly available resource of cognitive test data for over 21,000 adults aged 18 years and older. While valuable on its own, the CogCF may also be linked to an extensive range of other publicly available data collected in the UAS, including the complete Health and Retirement Study survey instrument and additional surveys on topics such as job history, personality, financial and psychological wellbeing, healthcare usage, and physical and mental health. These data enable researchers to examine critical questions such as the associations of cognitive ability with everyday life outcomes and factors associated with cognitive changes over the life course.

Socioeconomic status (SES) predicts age-related changes in health status; however, the source of SES-health associations is heavily debated. Twin studies allow tests of causal hypotheses by modeling within and between twin pair differences in longitudinal latent growth curve models (LGCM) of physical aging, examining level of functioning and rate of change with age. Three longitudinal twin studies of aging (mean age at baseline = 71.36, SD = 10.7) from the Swedish Twin Registry (N = 1369) included up to 27 years of follow-up on a Functional Aging Index (FAI) consisting of lung function, grip strength, walking speed, and self-report sensory functioning. SES indicators included education, financial strain, and occupation-based socioeconomic position. Pair means (between family effect) and within pair differences (within family effect) for SES were included as covariates of both intercept and slopes in a two-slope LGCM (intercept at age 75); models were corrected for sex and parental SES. LGCM results were compared across the full sample, then separately for both monozygotic and dizygotic twin pairs. Results indicated genetic confounding in the associations between multiple SES indicators and the FAI intercept. Additionally, the relationship between education longitudinal change in physical aging up to age 75 was subject to genetic confounding. These patterns were replicated among men. In contrast, findings for women pointed to shared environmental influences rather than genetic confounding, although statistical power was reduced in sex-stratified analyses. Results highlight the importance of considering the timing of socioeconomic exposures and gendered life-course trajectories when examining health inequalities in aging.

Purpose: In Sweden, in the wake of deinstitutionalization, in 1995 the responsibility for support regarding accommodation, employment, and an active everyday life for persons with severe mental illness (SMI) became a matter for the municipality’s social services. The overall aim of this study was to investigate whether there are differences in functioning and needs among older adults (65+) with severe mental illness (SMI) when divided into Psychosis and Non‑Psychosis groups.

Materials and methods: Data was collected from 5 surveys, and data from national registers. A group of older adults with SMI, with a history of long-term stays in mental hospitals, was identified and divided into two groups: Psychosis diagnosis (N = 222) and Non-Psychotic diagnosis (N = 253).

Results: The level of functioning was significantly lower in the Psychosis group, but at the same time, long periods of institutionalization, regardless of diagnosis category, also contributed to lower functioning scores. Diagnostic group did not explain differences in the proportion of unsatisfied needs; however, the length of institutionalization did.

Conclusions: Although there were diagnostic group differences in functioning, there were no diagnostic group differences in unmet needs, suggesting that social services were responding to individuals’ actual level of functioning. In line with the studies by Barton and by Goffman, it can be argued that the long periods of institutionalization were the most decisive factors influencing functional levels.

Background: Polygenic scores (PGSs) may help assess genetic predisposition to multifactorial traits. We examined whether age, sex, and leisure-time physical activity (LTPA) modify the association between a PGS for handgrip strength (HGS) and measured HGS in older adults.

Methods: PGS for HGS (PGShgs), based on Pan-UK Biobank GWAS data, was calculated for 5103 participants (aged 40–96; 44% women) from eight twin cohorts in Denmark, Sweden, Australia, the United States, and Finland within the IGEMS consortium. Sex-standardized HGS and self-reported LTPA were assessed cross-sectionally. Linear mixed models estimated associations between PGShgs and HGS, including interactions with age, country, and LTPA, as well as an association between PGShgs and LTPA. Fixed-effect within-pair models were conducted to assess environmental contributions.

Results: Higher PGShgs was associated with greater HGS (β = 2.14, SE = 0.15, p < 0.001), explaining 4.6% of HGS variance overall, with modest variation across countries. In sex-stratified models, PGShgs explained 5.2% of the variance in females and 4.3% in males. No statistically significant interaction with age was found. A significant PGShgs × LTPA interaction (β = –0.034, p = 0.013) indicated that the association between LTPA and HGS was more pronounced among individuals with lower PGShgs. The within-pair models offered limited support for the independent environmental impact of LTPA.

Conclusions: The PGShgs was associated with measured HGS in the meta-analysis, highlighting the potential of PGSs to capture individual differences in strength-related traits across populations. The association of PGShgs with HGS was moderated by LTPA, such that the beneficial impact of LTPA on HGS was greater among individuals with a lower genetic propensity for HGS.

Typing has become increasingly integral to everyday functioning. To comprehensively understand people’s level of functioning, researchers may also want to consider typing performance in addition to performance of other classical activities of daily living like dressing, shopping, or managing a budget. Classical typing tests are too burdensome to administer in panel studies. We examined functional and cognitive correlates of a one sentence typing speed test to examine if this brief measure could provide meaningful information. A sample of 10,613 adult participants in the Understanding America Study (UAS), a nationally representative longitudinal online survey panel, completed surveys, cognitive tests, and the typing test. Intraclass correlation coefficients of 0.79 for computer typing speed and 0.63 for smartphone typing speed suggested high test–retest stability for the brief typing test across 2 years. Faster typing speed was generally associated with better cognitive functioning across domains, fewer reported difficulties with basic and instrumental activities of daily living, and a lower likelihood of several self-reported illnesses. After adjustment for demographics, the correlation magnitudes were attenuated but still generally in the expected directions. Typing speed as captured by a single sentence typing speed test appeared to be sensitive to several measures relevant to everyday functioning. 

BACKGROUND: Leisure activity is associated with a wide range of physical and mental health outcomes. Nonetheless, the causal basis for these associations is uncertain and we do not fully understand why some individuals are active while others are sedentary.

METHODS: We investigated genetic and environmental contributions to individual differences in frequencies of social, physical, and intellectual leisure activities and their relationship to depressive symptoms, using data from the Interplay of Genes and Environment across Multiple Studies consortium. The sample consisted of 31 596 like-sex twins (44.1% monozygotic, 31.4% women, age range 32-99 years) representing 11 studies from Sweden, Denmark, United States, and Australia.

RESULTS: Results indicated moderate contributions of genetic factors to social (a2 = 0.26, 95% CI = 0.16; 0.35), physical (a2 = 0.39, CI = 0.28; 0.51), and intellectual (a2 = 0.47, CI = 0.33; 0.61) activities. The contribution of shared environmental factors (c2) was trivial, ranging from -0.03 to 0.02, while estimates of nonshared environmental factors (e2) were consistently substantial, ranging from 0.52 to 0.68. There was no evidence that estimates varied by age and limited evidence that they varied by sex and country. Co-twin control analyses revealed a significant negative within-pair association of depressive symptoms with each activity domain.

CONCLUSIONS: Although genetic factors contribute importantly to mid-to-late-life activity levels, associations of leisure activity levels with depressive symptoms remained significant when controlling for (unmeasured) genetic and shared environmental confounding. These findings are consistent with, albeit not proof of, a causal effect of leisure activities on depressive symptoms.

Introduction: Sleep health is a multifaceted concept including sleep duration, sleep continuity/efficiency, timing, alertness during waking hours, and perceived sleep quality. Among older adults, sleep disturbances are common and linked to adverse health outcomes such as frailty, physical and mental health issues, increased healthcare utilization, and mortality. Despite the high prevalence of poor sleep health among older people, the broader concept of sleep health in community-dwelling older populations has not been comprehensively reviewed. The aim of the study was to synthesize existing knowledge on sleep health among community dwelling older adults (aged 65 and over), covering all five core dimensions of sleep health. The review also sought to identify key knowledge gaps and future research priorities.

Materials and methods: The review followed a systematic scoping methodology. Literature searches were conducted in Medline, CINAHL, and PsycINFO to identify peer-reviewed studies published in English or Swedish that included participants aged ≥65 years living in community settings. Only studies addressing all five sleep health dimensions were included. Data results on sample size, sleep variables, and health outcomes were extracted and synthesized.

Results: Eight studies met the inclusion criteria, where seven studies originated from USA and one study from Taiwan. Seven studies were based on data from a male and female osteoporosis registry. The studies had sample sizes ranging from 1,413 to 6,485 with a mean age between 76– 83.6. The findings suggest that multidimensional sleep health is an important indicator of well-being in older adults. Poor sleep health, especially when two or more dimensions are impaired, was associated with higher risks of depression, higher healthcare cost, and mortality. Sexbased differences were notable: women reported poorer sleep and more frequent daytime napping, which itself was linked to higher mortality. In contrast, individuals reporting better sleep health had lower odds of frailty. Very few studies included adults aged 80 and above, limiting generalizability to the oldest-old population.

Conclusions: The scoping review highlights a clear need for more nuanced and inclusive research on sleep health in community-dwelling older populations. Future studies should include diverse samples, particularly the oldest age groups, and account for contextual factors such as care settings and sleep medication use. A more comprehensive understanding of sleep health is essential for developing effective interventions to support successful healthy aging.

While education is among the most consistent predictors of cognitive health and dementia risk, it is unclear whether this reflects the benefits of schooling itself or other factors such as underlying genetic predispositions or family-based inequality. Further, the benefits of education to cognitive health may be dependent on larger structures of inequality. Using data from the IGEMS Consortium of over 4500 twins from seven cohorts in the USA, Sweden, Denmark, and Australia, we examine how genetic propensity for education and national/historical contexts of inequality shape dementia risk in later life. Dementia risk was measured with the Latent Dementia Index, a validated continuous indicator of likelihood of dementia, while key predictors included both attained education, a polygenic score for educational attainment (PGS-ED), and cohort- and country-specific Gini indices of educational inequality (GINI-ED). Ordinary least squares and within–between twin models were estimated to separate between-family from within-family effects. Results confirm that higher education is associated with lower likelihood of dementia; PGS-ED also predicts likelihood of dementia, although both associations are attenuated when comparing twins within families. Country-level educational inequality moderated these effects; education—and to a lesser extent PGS-ED—were stronger predictors of cognition in more egalitarian contexts. Our findings emphasize the interplay of both genes and social factors in potentially shaping dementia.

Young-onset dementia occurs during life stages when work and family responsibilities may still be present. These circumstances mean that persons with young-onset dementia often face support systems that are not fully adapted to their age, needs, or daily life. Although family-centred approaches are increasingly recognised in dementia care, limited knowledge exists about how couples living with young-onset dementia understand and make use of support in daily life. This study explores how support is experienced and integrated into the shared lifeworld of couples, focusing on practical, emotional, and existential aspects of daily living. Eleven couples participated in dyadic, semi-structured interviews. A meaning-oriented thematic analysis, guided by lifeworld research, was used to explore how support is understood and incorporated into daily life. Three themes emerged. Negotiating independence and support in daily life describes how couples balance emerging needs with daily routines and autonomy. Navigating complex systems in search of adequate support highlights the challenges of encountering fragmented structures and unclear responsibilities, often requiring persistence to identify relevant services. Experiencing a balance between expectations and daily support shows how support becomes meaningful when it aligns with the couple’s daily life and current needs. Overall, the themes demonstrate how couples work together to maintain daily life while managing emerging needs and navigating fragmented systems, and how support is most helpful when it fits their life situation. The findings underscore the importance of support that matches the life circumstances of couples living with young-onset dementia and the ways they make sense of their daily lives.

OBJECTIVES: Birth weight is a widely used indicator of prenatal experiences in models of the developmental origins of cognitive ability across the lifespan. This study aimed to examine the association between birth weight and cognitive ability using a community sample of twins followed prospectively from infancy to midlife. We leveraged the twin study design to identify phenotypic and biometric associations between the two constructs.

METHODS: The sample consisted of 1,501 participants (387 dizygotic pairs, 360 monozygotic pairs, and 7 singletons; 53.1% female; 91.1% White) from the Louisville Twin Study. We modeled the change in the strength of the association between birth weight and cognitive ability using exponential decay functions.

RESULTS: The magnitude of the association between birth weight and cognitive ability declined exponentially from infancy (β = .59, p < .05) to midlife (β = .27, p < .05). The lower asymptote of the exponential decay function was reached at about age 2.5 years of age, after which the association between birth weight and cognitive ability stabilized and remained constant up to midlife. A 1-kilogram increase in birth weight was associated with an 8.85-point increase in cognitive scores at 3 months and a 4.05-point advantage after about 2.5 years. Biometric regression models revealed that shared environmental factors accounted for the decline in the association between birth weight and cognitive ability. A small, positive within-pair association persisted into midlife.

DISCUSSION: These findings suggest that prenatal experiences may have lasting effects on cognitive development across the lifespan, supporting developmental origin models of cognitive ability.