Social health and subsequent cognitive functioning in people aged 50 years and older: examining the mediating roles of depressive symptoms and inflammatory biomarkers in two European longitudinal studies.

BACKGROUND: Social health markers, including marital status, contact frequency, network size, and social support, have been shown to be associated with cognition. However, the mechanisms underlying these associations remain poorly understood. We investigated whether depressive symptoms and inflammation mediated associations between social health and subsequent cognition. METHODS: In the English Longitudinal Study of Ageing (ELSA), a nationally representative longitudinal study in England, UK, we sampled 7136 individuals aged 50 years or older living in private households without dementia at baseline or at the intermediate mediator assessment timepoint, who had recorded information on at least one social health marker and potential mediator. We used four-way decomposition to examine to what extent depressive symptoms, C-reactive protein, and fibrinogen mediated associations between social health and subsequent standardised cognition (verbal fluency and delayed and immediate recall), including cognitive change, with slopes derived from multilevel models (12-year slope). We examined whether findings were replicated in the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), a population-based longitudinal study in Sweden, in a sample of 2604 individuals aged 60 years or older living at home or in institutions in Kungsholmen (central Stockholm) without dementia at baseline or at the intermediate mediator assessment timepoint (6-year slope). Social health exposures were assessed at baseline, potential mediators were assessed at an intermediate timepoint (wave 2 in ELSA and 6-year follow-up in SNAC-K); cognitive outcomes were assessed at a single timepoint (wave 3 in ELSA and 12-year follow-up in SNAC-K), and cognitive change (between waves 3 and 9 in ELSA and between 6-year and 12-year follow-ups in SNAC-K). FINDINGS: The study sample included 7136 participants from ELSA, of whom 3962 (55·5%) were women and 6934 (97·2%) were White; the mean baseline age was 63·8 years (SD 9·4). Replication analyses included 2604 participants from SNAC-K, of whom 1604 (61·6%) were women (SNAC-K did not collect ethnicity data); the mean baseline age was 72·3 years (SD 10·1). In ELSA, we found indirect effects via depressive symptoms of network size, positive support, and less negative support on subsequent verbal fluency, and of positive support on subsequent immediate recall (pure indirect effect [PIE] 0·002 [95% CI 0·001-0·003]). Depressive symptoms also partially mediated associations between less negative support and slower decline in immediate recall (PIE 0·001 [0·000-0·002]) and in delayed recall (PIE 0·001 [0·000-0·002]), and between positive support and slower decline in immediate recall (PIE 0·001 [0·000-0·001]). We did not observe mediation by inflammatory biomarkers. Findings of mediation by depressive symptoms in the association between positive support and verbal fluency and between positive support and change in immediate recall were replicated in SNAC-K. INTERPRETATION: The findings of this study provide new insights into mechanisms linking social health with cognition, suggesting that associations between interactional aspects of social health, especially social support, and cognition are partly underpinned by depressive symptoms. FUNDING: EU Joint Programme-Neurodegenerative Disease Research (JPND) and Alzheimer's Society. TRANSLATION: For the Swedish translation of the abstract see Supplementary Materials section.

Weakening of the cognition and height association from 1957 to 2018: Findings from four British birth cohort studies.

Background: Taller individuals have been repeatedly found to have higher scores on cognitive assessments. Recent studies have suggested that this association can be explained by genetic factors, yet this does not preclude the influence of environmental or social factors that may change over time. We thus tested whether the association changed across time using data from four British birth cohorts (born in 1946, 1958, 1970, and 2001). Methods: In each cohort height was measured and cognition via verbal reasoning, vocabulary/comprehension, and mathematical tests; at ages 10/11 and 14/17 years (N=41,418). We examined associations between height and cognition at each age, separately in each cohort, and for each cognitive test administered. Linear and quantile regression models were used. Results: Taller participants had higher mean cognitive assessment scores in childhood and adolescence, yet the associations were weaker in later (1970 and 2001) cohorts. For example, the mean difference in height comparing the highest with lowest verbal cognition scores at 10/11 years was 0.57 SD (95% CI = 0.44-0.70) in the 1946 cohort, yet 0.30 SD (0.23-0.37) in the 2001 cohort. Expressed alternatively, there was a reduction in correlation from 0.17 (0.15-0.20) to 0.08 (0.06-0.10). This pattern of change in the association was observed across all ages and cognition measures used, was robust to adjustment for social class and parental height, and modeling of plausible missing-not-at-random scenarios. Quantile regression analyses suggested that these differences were driven by differences in the lower centiles of height, where environmental influence may be greatest. Conclusions: Associations between height and cognitive assessment scores in childhood-adolescence substantially weakened from 1957-2018. These results support the notion that environmental and social change can markedly weaken associations between cognition and other traits. Funding: DB is supported by the Economic and Social Research Council (grant number ES/M001660/1); DB and LW by the Medical Research Council (MR/V002147/1). The Medical Research Council (MRC) and the University of Bristol support the MRC Integrative Epidemiology Unit [MC_UU_00011/1]. NMD is supported by an Norwegian Research Council Grant number 295989. VM is supported by the CLOSER Innovation Fund WP19 which is funded by the Economic and Social Research Council (award reference: ES/K000357/1) and Economic and Social Research Council (ES/M001660/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Midlife Health in Britain and the US: A comparison of Two Nationally Representative Cohorts.

Background: Older adults in the United States (US) have worse health and wider socioeconomic inequalities in health compared to Britain. Less is known about how health in the two countries compares in midlife, a time of emerging health decline, including inequalities in health. Methods: We compare measures of smoking status, alcohol consumption, obesity, self-rated health, cholesterol, blood pressure, and glycated haemoglobin using population-weighted modified Poisson regression in the 1970 British Cohort Study (BCS70) in Britain (N= 9,665) and the National Longitudinal Study of Adolescent to Adult Health (Add Health) in the US (N=12,297), when cohort members were aged 34-46 and 33-43, respectively. We test whether associations vary by early- and mid-life socioeconomic position. Findings: US adults had higher levels of obesity, high blood pressure and high cholesterol. Prevalence of poor self-rated health, heavy drinking, and smoking was worse in Britain. We found smaller socioeconomic inequalities in midlife health in Britain compared to the US. For some outcomes (e.g., smoking), the most socioeconomically advantaged group in the US was healthier than the equivalent group in Britain. For other outcomes (hypertension and cholesterol), the most advantaged US group fared equal to or worse than the most disadvantaged groups in Britain. Interpretation: US adults have worse cardiometabolic health than British counterparts, even in early midlife. The smaller socioeconomic inequalities and better overall health in Britain may reflect differences in access to health care, welfare systems, or other environmental risk factors. Funding: ESRC, UKRI, MRC, NIH, European Research Council, Leverhulme Trust.

Investigating change across time in prevalence or association: the challenges of cross-study comparative research and possible solutions.

Cross-study research initiatives to understand change across time are an increasingly prominent component of social and health sciences, yet they present considerable practical, analytical and conceptual challenges. First, we discuss the key challenges to comparative research as a basis for detecting societal change, as well as possible solutions. We focus on studies which investigate changes across time in outcome occurrence or the magnitude and/or direction of associations. We discuss the use and importance of such research, study inclusion, sources of bias and mitigation, and interpretation. Second, we propose a structured framework (a checklist) that is intended to provide guidance for future authors and reviewers. Third, we outline a new open-access teaching resource that offers detailed instruction and reusable analytical syntax to guide newcomers on techniques for conducting comparative analysis and data visualisation (in both R and Stata formats). Supplementary Information: The online version contains supplementary material available at 10.1007/s44155-022-00021-1.

Building a transdisciplinary expert consensus on the cognitive drivers of performance under pressure: An international multi-panel Delphi study.

Introduction: The ability to perform optimally under pressure is critical across many occupations, including the military, first responders, and competitive sport. Despite recognition that such performance depends on a range of cognitive factors, how common these factors are across performance domains remains unclear. The current study sought to integrate existing knowledge in the performance field in the form of a transdisciplinary expert consensus on the cognitive mechanisms that underlie performance under pressure. Methods: International experts were recruited from four performance domains [(i) Defense; (ii) Competitive Sport; (iii) Civilian High-stakes; and (iv) Performance Neuroscience]. Experts rated constructs from the Research Domain Criteria (RDoC) framework (and several expert-suggested constructs) across successive rounds, until all constructs reached consensus for inclusion or were eliminated. Finally, included constructs were ranked for their relative importance. Results: Sixty-eight experts completed the first Delphi round, with 94% of experts retained by the end of the Delphi process. The following 10 constructs reached consensus across all four panels (in order of overall ranking): (1) Attention; (2) Cognitive Control-Performance Monitoring; (3) Arousal and Regulatory Systems-Arousal; (4) Cognitive Control-Goal Selection, Updating, Representation, and Maintenance; (5) Cognitive Control-Response Selection and Inhibition/Suppression; (6) Working memory-Flexible Updating; (7) Working memory-Active Maintenance; (8) Perception and Understanding of Self-Self-knowledge; (9) Working memory-Interference Control, and (10) Expert-suggested-Shifting. Discussion: Our results identify a set of transdisciplinary neuroscience-informed constructs, validated through expert consensus. This expert consensus is critical to standardizing cognitive assessment and informing mechanism-targeted interventions in the broader field of human performance optimization.

Influence of childhood socioeconomic position and ability on mid-life cognitive function: evidence from three British birth cohorts.

BACKGROUND: Childhood socioeconomic position (SEP) is robustly associated with cognitive function later in life. However, it is unclear whether this reflects a direct relationship, or an indirect association via modifiable factors such as educational attainment and occupation. We sought to clarify these associations using retrospectively harmonised data from three ongoing British birth cohorts. METHODS: We analysed data from the 1946 National Survey of Health and Development (n=2283), the 1958 National Child Development Study (n=9385) and the 1970 British Cohort Study (n=7631). Retrospective harmonisation was used to derive equivalent indicators of cognition, SEP, education and occupation across the three cohorts. Structural equation modelling was used to examine the association between childhood SEP and mid-life cognitive function, via childhood cognitive ability, educational attainment and mid-life occupation. RESULTS: Across all three cohorts, no direct pathways were observed between childhood SEP and mid-life cognitive function. Rather, this association was indirect via the three temporally ordered mediators. In addition, the direct pathway between childhood cognition and adult cognitive function was weaker in the two younger studies. CONCLUSIONS: Across three British birth cohorts, we found that the association between early life SEP and mid-life cognitive function was fully mediated by childhood cognitive ability, educational attainment and occupational status. Furthermore, the association between early cognitive ability and mid-life cognitive function has decreased in younger generations. Therefore, cognitive function in adulthood may be influenced by modifiable factors and societal change.

The intergenerational transmission of language skill.

This paper examines the relationship between parents' and children's language skills for a nationally representative birth cohort born in the United Kingdom-the Millennium Cohort Study (MCS). We investigate both socioeconomic and ethnic differentials in children's vocabulary scores and the role of differences in parents' vocabulary scores in accounting for these. We find large vocabulary gaps between highly educated and less educated parents, and between ethnic groups. Nevertheless, socioeconomic and ethnic gaps in vocabulary scores are far wider among the parents than among their children. Parental vocabulary is a powerful mediator of inequalities in offspring's vocabulary scores at age 14, and also a powerful driver of change in language skills between the ages of five and 14. Once we account for parental vocabulary, no ethnic minority group of young people has a negative "vocabulary gap" compared to whites.

Collection of genetic data at scale for a nationally representative population: the UK Millennium Cohort Study.

A DNA bank has been created from the Millennium Cohort Study (MCS) saliva samples. A total of 23,336 samples are available, from 9,259 cohort members (4,630 males and 4,629 females), 8,898 mothers and 5,179 fathers. There are 4,533 mother, child, father 'triads'. This paper describes the collection of the saliva samples from cohort members and their biological parents in the MCS. It analyses response rates and predictors of response, and details the DNA extraction, genotyping and imputation procedures performed on the data.

Parental Wealth and Children's Cognitive Ability, Mental, and Physical Health: Evidence From the UK Millennium Cohort Study.

This article investigates the influence of wealth, a frequently neglected aspect of the economic circumstances of families, on children's development. Using the UK Millennium Cohort Study, it explores whether parental wealth (net total wealth, net housing wealth, net financial wealth, and house value) is associated with children's cognitive ability, mental, and physical health at age 11 (N = 8,645), over and above parental socioeconomic status and economic resources, in particular permanent income. Housing wealth was associated with fewer emotional and behavioral problems, independent of the full set of controls. Children's verbal cognition and general health were more strongly associated with family permanent income and socioeconomic characteristics than with wealth.

The role of intelligence in decision-making in early adolescence.

This study investigated the role of intelligence and its development across childhood in decision-making in adolescence (age 11 years). The sample was 12,514 children from the UK's Millennium Cohort Study, followed at ages 3, 5, 7, and 11 years. Decision-making (risk-taking, quality of decision-making, risk adjustment, deliberation time, and delay aversion) was measured with the Cambridge Gambling Task. Even after adjustment for confounding, intelligence was positively associated with risk adjustment and quality of decision-making in both boys and girls. Furthermore, in girls risk adjustment was related positively to IQ gains. Our findings suggest that there are important, substantively, associations between intelligence and adapting behaviour to risk at the cusp of adolescence, the period when the response to risk can shape life trajectories. Statement of Contribution What is already known on this subject In children, intelligence and decision-making, measured with gambling tasks, are inconsistently linked. This could be due to gambling tasks not separating risk-taking from contingency-learning. What the present study adds This study measured 11-year-olds' decision-making using a gambling task in which probabilities of different outcomes are presented explicitly. IQ was positively associated with risk adjustment and quality of decision-making. Also significant were IQ gains (for risk adjustment, only in girls). There are links between intelligence and adapting behaviour to statistical risk in children.

Cross-Domain Symptom Development Typologies and Their Antecedents: Results From the UK Millennium Cohort Study.

OBJECTIVE: Typologies of symptom development have been used to identify individuals with different symptom development in the externalizing and internalizing domains of child psychopathology separately despite the domains' high comorbidity and shared common etiologic risk. This study identified typologies of development jointly across the 2 symptom domains in childhood and investigated their associated antecedents with a specific focus on the comparisons between overall severity of symptoms and symptom expression in one or the other domain. METHOD: Latent class analysis identified groups based on emotional and behavioral symptoms assessed at 3, 5, 7, and 11 years in the UK Millennium Cohort Study (N = 15,439). Different sociodemographic, family structure and environment, birth, infancy, and early childhood antecedents were examined. RESULTS: Five groups were identified: 1. low symptoms (57%), 2. moderate behavioral (21%), 3. moderate emotional (12.5%), 4. high emotional and moderate behavioral (5.5%), and 5. high behavioral and moderate emotional (4%). Higher symptoms were predicted by larger numbers of antecedents and risk factors compared with the low symptom group and compared with moderate and high levels of symptoms in either domain (groups 5 versus 2 and 4 versus 3). Comparisons of groups with similar overall symptom levels but different dominant symptom domain (groups 2 versus 3 and 4 versus 5) indicated that apart from gender and ethnicity, there were few unique antecedents of whether children mainly internalize or externalize their symptoms. CONCLUSION: It is possible and useful to define groupings or typologies jointly across externalizing and internalizing symptom development in childhood. Although numerous antecedents predict the experience of symptoms, there are few unique antecedents that differentiate individuals with similarly high levels of psychopathology expressed mainly as internalizing or externalizing symptoms. Identification of at-risk children and delivery of early intervention might benefit from a decreased focus on symptom domain with possible downstream effects through the life course for most common psychiatric disorders.

The role of socio-economic disadvantage in the development of comorbid emotional and conduct problems in children with ADHD.

Previous research shows that, compared to children without ADHD, children with ADHD have worse socio-emotional outcomes and more experience of socio-economic disadvantage. In this study, we explored if and how the increased emotional and behavioural difficulties faced by children with ADHD may be accounted for by their more disadvantaged socio-economic circumstances. Our study, using data from 180 children (149 boys) with ADHD from the Millennium Cohort Study, had two aims. First, to examine the role of socio-economic disadvantage in the trajectories of emotional and conduct problems in children with ADHD at ages 3, 5, 7 and 11 years. Second, to explore the roles of the home environment (household chaos) and parenting (quality of emotional support, quality of the parent-child relationship and harsh parental discipline) in mediating any associations between socio-economic disadvantage and child emotional and conduct problems. Using growth curve models, we found that socio-economic disadvantage was associated with emotional and conduct problems but neither the home environment nor parenting attenuated this association. Lower quality of the parent-child relationship and harsher discipline were associated with more conduct problems. It appears that socio-economic disadvantage and parenting contribute independently to the prediction of comorbid psychopathology in children with ADHD.