National Child Development Study Research Articles

Mid-life social participation in people with intellectual disability: The 1958 British birth cohort study.

Low social participation is a potentially modifiable risk factor for cognitive deterioration in the general population and related to lower quality of life (QoL). We aimed to find out whether social participation is linked to cognitive deterioration and QoL for people with borderline intellectual functioning and mild intellectual disability. We used data from the National Child Development Study, consisting of people born during one week in 1958, to compare midlife social participation in people with mild intellectual disability, borderline intellectual functioning, and without intellectual impairment. We defined social participation as 1. confiding/emotional support from the closest person and social network contact frequency at age 44, and 2. confiding relationships with anyone at age 50. We then assessed the extent to which social participation mediated the association between childhood intellectual functioning and cognition and QoL at age 50. 14,094 participants completed cognitive tests at age 11. People with borderline intellectual functioning and mild intellectual disability had more social contact with relatives and confiding/emotional support from their closest person, but fewer social contacts with friends and confiding relationships with anyone than those without intellectual disability. Having a confiding relationship partially mediated the association at age 50 between IQ and cognition (6.4%) and QoL (27.4%) for people with borderline intellectual functioning. We found adults with intellectual disability have positive family relationships but fewer other relationships. Even at the age of 50, confiding relationships may protect cognition for people with borderline intellectual functioning and are important for QoL.

Childhood Reading Ability and Pain in Childhood Through to Midlife

Dyslexia and pain have recently been shown to correlate on a genetic level, but there has been little exploration of this association on the phenotypic level despite reports of increased pain in Attention Deficit Hyperactivity Disorder, which commonly co-occurs with dyslexia. In this study we test for an association between reading ability, which is the primary feature of dyslexia, and pain both in childhood and adulthood. Logistic regression modeling was used to test associations between reading ability in childhood and pain from childhood to midlife in a large UK birth cohort; the 1958 National Child Development Study. Associations were found between poor childhood reading ability and increased headache and abdominal pain in childhood, and between poor childhood reading ability and headache, eye pain, back pain, and rheumatism in adulthood. Mediation analyses indicated that socioeconomic status (defined by employment) fully mediated the association between poor reading ability in childhood and back pain at age 42. By contrast, the association between reading ability and eye pain acted independently of socioeconomic status. Different mechanisms were thus indicated for the association of reading with different pain types, including manual labor and a potential shared biological pathway. PerspectiveThis study found a relationship between poor reading ability in childhood and pain in childhood and adulthood. Those with reading difficulties should be monitored for pain symptoms. Future research may uncover shared biological mechanisms, increasing our understanding of pain and potential treatments.

Association of physical and sexual assault with mortality in two British birth cohorts

AimsThe association of assault in adulthood with all-cause mortality, and the relevance of intermediate psychological distress, alcohol use and cigarette smoking, is poorly understood. We used data from British birth...

Early-life cumulative exposure to excess bodyweight and midlife cognitive function: longitudinal analysis in three British birth cohorts

Excess bodyweight (BMI >25 kg/m2) in midlife (age 40-65 years) has been linked to future cognitive decline and an increased risk of dementia. Whether chronic exposure to excess bodyweight in the early decades of life (<40 years) is associated with compromised cognitive function by midlife, however, remains unclear. This study therefore aimed to test potential bidirectional direct and indirect pathways linking cumulative exposure to excess bodyweight and cognitive function in the early decades of life. In this longitudinal analysis, harmonised measures of BMI and cognitive function were available in 19 742 participants aged 47-53 years recruited to the 1946 National Survey of Health and Development (n=2131), the 1958 National Child Development Study (n=9385), and the 1970 British Cohort Study (n=8226). Individual BMI trajectories spanning three decades from age 10-40 years were created for each participant and excess bodyweight duration, BMI change between ages, and cumulative excess bodyweight exposure were calculated. Harmonised measures of verbal and non-verbal ability, mathematical ability, and reading ability were used to create a latent factor for childhood cognitive function, and immediate and delayed recall, animal naming, and letter-search speed tests were used for midlife cognitive function. Multivariable linear regression and structural equation models (SEM) were used to test for potential bidirectional relationships between cognition and excess bodyweight in both individual cohorts and pooled datasets while accounting for other potential early-life confounders. Increases in BMI during adolescence and greater cumulative exposure to excess bodyweight across early life were associated with lower midlife cognitive function in all cohorts (eg, pooled difference in cognitive function per 10 years excess bodyweight duration -0·10; 95% CI -0·12 to -0·08; p<0·001). Further adjustment for childhood cognitive function attenuated many of these associations towards the null (eg, pooled difference in cognitive function per 10 years excess bodyweight duration -0·04; 95% CI -0·06 to -0·02; p=0·001), however, with any remaining associations then fully attenuating once further adjusted for other early-life factors (eg, pooled difference in cognitive function per 10 years excess bodyweight duration 0, -0·03 to 0·01; p=0·38). In the reverse direction, low childhood cognition was associated with greater cumulative exposure to excess bodyweight over the next four decades, although much of this relationship was found to probably be explained via other potentially modifiable upstream early-life factors such as childhood disadvantage. SEM in all cohorts suggested the presence of modest direct and indirect pathways connecting earlier cognitive function to later excess bodyweight, but scarce evidence for an effect of early-life excess bodyweight on cognitive function by midlife. The association between cumulative exposure to excess bodyweight in early life and lower cognitive function in midlife is probably confounded by a persistently lower cognitive function from childhood. Initiatives to improve early-life factors such as childhood disadvantage and education, however, might exert dual but independent benefits on both of these factors before old age. Alzheimer's Research UK, Diabetes Research and Wellness Foundation, Diabetes UK, British Heart Foundation, and Medical Research Council.

Does higher education matter for health in the UK?

Using six sweeps of data from the 1958 British National Child Development Study (NCDS), we employ a quasi-parametric approach of propensity score matching to estimate the impacts of higher education attainment on a wide range of health-related outcomes for cohorts at ages 33, 42, and 50. The non-pecuniary benefits of higher education on health are substantial. Cohorts with higher levels of education are more likely to report better health, maintain a healthy weight, refrain from smoking, exhibit a lower frequency of alcohol consumption, and are less likely to be obese. The effects on self-reported health, body mass index (BMI), drinking alcohol increase with age, but continuously decrease with smoking frequency. When considering gender heterogeneity, higher education has a more significant effect on BMI and the likelihood of obesity for males, while it has a greater impact on self-reported health, drinking alcohol, and smoking frequencies for females. Furthermore, we find no significant evidence that higher education reduces the likelihood of depression. The results of the Rosenbaum bounds sensitivity analysis suggest that, although our overall results demonstrate robustness, there may still be unobserved hidden bias in the relationship between higher education and self-reported health.

An Analysis of the Effect of Streaming on Civic Participation Through a Causal Hidden Markov Model

We examine the effect of streaming based on ability levels on individuals’ civic participation throughout their adult life. The hypothesis we test is that ability grouping influences individuals’ general self-concept and, consequently, their civic participation choices across the life course. We employ data from the British National Child Development Study, which follows all UK citizens born during a certain week in 1958. Six binary variables observed at 33, 42, and 51 years of age are considered to measure civic participation. Our approach defines causal estimands with multiple treatments referring to the evolution of civic engagement over time in terms of potential versions of a sequence of latent variables assumed to follow a Markov chain with initial and transition probabilities depending on posttreatment time-varying covariates. The model also addresses partially or entirely missing data on one or more indicators at a given time occasion and missing posttreatment covariate values using dummy indicators. The model is estimated by maximizing a weighted log-likelihood function with weights corresponding to the inverse probability of the received treatment obtained from a multinomial logit model based on pretreatment covariates. Our results show that ability grouping affects the civic participation of high-ability individuals when they are 33 years old with respect to participation in general elections.

Estimation of Causal Effects with a Binary Treatment Variable: A Unified M-Estimation Framework

Abstract In this paper, we review several estimators of the average treatment effect (ATE) that belong to three main groups: regression, weighting and doubly robust methods. We unify the exposition of these estimators within an M-estimation framework and we derive their variance estimators from the sandwich form variance-covariance matrix of the M-Estimator. Additionally, we re-estimate the causal return to higher education on earnings by the reviewed methods using the rich dataset provided by the British National Child Development Study (NCDS) as an empirical illustration.

Early life stress in relation with risk of overweight, depression, and their comorbidity across adulthood: findings from a British birth cohort.

Multimorbidity, known as the co-occurrence of at least two chronic conditions, has become of increasing concern in the current context of ageing populations, though it affects all ages. Early life risk factors of multimorbidity include adverse childhood experiences (ACEs), particularly associated with psychological conditions and weight problems. Few studies have considered related mechanisms and focus on old age participants. We are interested in estimating, from young adulthood, the risk of overweight-depression comorbidity related to ACEs while adjusting for early life confounders and intermediate variables. We used data from the 1958 National Child Development Study, a prospective birth cohort study (N = 18 558). A four-category outcome (no condition, overweight only, depression only and, overweight-depression comorbidity) was constructed at 23, 33, and 42 years. Multinomial logistic regression models adjusting for intermediate variables co-occurring with this outcome were created. ACEs and sex interaction on comorbidity risk was tested. In our study sample (N = 7762), we found that ACEs were associated with overweight-depression comorbidity risk throughout adulthood (RRR [95% CI] at 23y = 3.80 [2.10-6.88]) though less overtime. Comorbidity risk was larger than risk of separate conditions. Intermediate variables explained part of the association. After full-adjustment, an association remained (RRR [95% CI] at 23y = 2.00 [1.08-3.72]). Comorbidity risk related to ACEs differed by sex at 42. Our study provides evidence on the link and potential mechanisms between ACEs and the co-occurrence of mental and physical diseases throughout the life-course. We suggest addressing ACEs in intervention strategies and public policies to go beyond single disease prevention.

Examining the quality and population representativeness of linked survey and administrative data: guidance and illustration using linked 1958 National Child Development Study and Hospital Episode Statistics data.

Recent years have seen an increase in linkages between survey and administrative data. It is important to evaluate the quality of such data linkages to discern the likely reliability of ensuing research. Evaluation of linkage quality and bias can be conducted using different approaches, but many of these are not possible when there is a separation of processes for linkage and analysis to help preserve privacy, as is typically the case in the UK (and elsewhere). We aimed to describe a suite of generalisable methods to evaluate linkage quality and population representativeness of linked survey and administrative data which remain tractable when users of the linked data are not party to the linkage process itself. We emphasise issues particular to longitudinal survey data throughout. Our proposed approaches cover several areas: i) Linkage rates, ii) Selection into response, linkage consent and successful linkage, iii) Linkage quality, and iv) Linked data population representativeness. We illustrate these methods using a recent linkage between the 1958 National Child Development Study (NCDS; a cohort following an initial 17,415 people born in Great Britain in a single week of 1958) and Hospital Episode Statistics (HES) databases (containing important information regarding admissions, accident and emergency attendances and outpatient appointments at NHS hospitals in England). Our illustrative analyses suggest that the linkage quality of the NCDS-HES data is high and that the linked sample maintains an excellent level of population representativeness with respect to the single dimension we assessed. Through this work we hope to encourage providers and users of linked data resources to undertake and publish thorough evaluations. We further hope that providing illustrative analyses using linked NCDS-HES data will improve the quality and transparency of research using this particular linked data resource.

Life-Course Socioeconomic Position and Mild Cognitive Impairment in Midlife: Evidence from the 1958 British Birth Cohort

BackgroundDementia has been the leading cause of death in the UK since 2015. Increasing evidence supports an association between socioeconomic position (SEP) and dementia onset in later life. However, limited studies have examined how life-course SEP influences the development of mild cognitive impairment (MCI), an intermediate state potentially preceding dementia. Therefore, the present study aims to examine the relationship between life-course SEP and MCI amongst adults aged 50 years in Great Britain.MethodsWe employed data from the National Child Development Study (NCDS), also known as the 1958 British Birth Cohort, to determine the associations between SEP and MCI in 6590 participants. We categorised life-course measures of SEP as stable high/low or moving upward/downward over the life course. We assessed MCI at age 50 using one standard deviation below the averaged combined scores from all cognitive tests available. We then used binary logistic regression to estimate the longitudinal associations between life-course SEP and MCI.ResultsRelative to those of a high SEP across the life course, participants who moved upward, downward, or remained at a low SEP were significantly associated with 25% (95% CI 1.02–1.54, p = 0.035), 70% (95% CI 1.27–2.27, p < 0.001), and 85% (95% CI 1.50–2.29, p < 0.001), respectively, higher odds of MCI, independent of all selected covariates.ConclusionsLower life-course SEP was associated with significantly higher odds of MCI onset in middle life within the NCDS cohort. Public health policies targeting cognitive impairment should encompass a life-course approach to reduce socioeconomic inequalities.

In the Words of Early Adolescents: A Novel Assessment of Positive Psychological Well-Being Predicts Young Adult Depressive Symptoms

PurposeGiven the burden of depression in young adulthood, identifying protective early life factors is important. Protective factors like positive psychological well-being may be challenging to assess via conventional methods if early adolescents lack personal insight or informants disagree. We investigated whether essays written by 11-year-olds could indicate the presence of positive psychological well-being and predict depressive symptom levels in young adulthood, beyond informant reports of problematic behaviors. MethodsData were from 4,599 individuals in the 1958 National Child Development Study who wrote an essay at age 11 about how they imagined their life at age 25. Coders rated essays for seven facets of positive psychological well-being, which were averaged together (α = 0.92). Participants self-reported depressive symptoms (yes/no) at age 23 on the 24-item Malaise Inventory. Depressive symptoms were modeled as a sum, both continuously (range = 0–24) and dichotomously (depressed: total scores ≥8). Linear and logistic regressions adjusted for relevant age 11 covariates including teacher-reported internalizing and externalizing behaviors. ResultsUnadjusted logistic regression showed a 1-SD higher positive psychological well-being score in early adolescence was associated with reduced odds of being depressed 12 years later (odds ratio = 0.83, 95% confidence interval [0.75, 0.93], p = .001). Associations remained when adjusting for all covariates (odds ratio = 0.87, 95% confidence interval [0.78, 0.98], p = .02); patterns were similar with continuous depressive symptoms. DiscussionA well-being measure derived from the words of 11-year-olds was associated with young adult depressive symptoms independent of teacher-reported internalizing and externalizing behaviors. Incorporating early adolescents' perspectives on positive functioning provides valuable information about current and future health beyond problem behaviors.

The general factor of personality as a female-typical trait

General factor of personality (GFP) is a central concept in personality and individual differences. Various scholars have suggested that GFP is an indicator of social effectiveness, emotional intelligence, or slow life history. Because women have advantage over men in all three, women should have higher levels of GFP than men regardless of its true nature. Analyses of the National Child Development Study in the UK (Study 1; n = 17,419) and the National Longitudinal Study of Adolescent to Adult Health in the US (Study 2; n = 20,745) confirmed the hypothesis. Women had substantially higher levels of GFP than men did in both nations. Study 3 made the first attempt to extract a macrolevel GFP (the Big Big One) from aggregate data (mean Big Five personality factors in US states). The macrolevel GFP was also a female-typical trait, being significantly correlated with the proportion female in the state samples. The results from all three studies show that GFP is a female-typical trait.

The effect of smoking initiation in adolescence on the subsequent smoking trajectories of people who smoke, and the role of adverse childhood experiences: Results from the 1958 British cohort study.

To examine the association between smoking initiation in adolescence and subsequent different smoking trajectories of people who smoke, and to examine the combined effect of adverse childhood experiences (ACEs) and smoking initiation in adolescence on smoking trajectories of people who smoke. Data are from 8757 individuals in Great Britain from the birth cohort National Child Development Study and who reported being smokers or former smokers by age 23. Smoking initiation in adolescence was measured at 16 y and smoking trajectories were derived from smoking variables from ages 23 to 55. We modelled the relationship between smoking initiation in adolescence with or without ACEs and smoking trajectories. Individuals who initiated smoking in adolescence were more likely to quit later than quitting in twenties (RRR quitting in thirties =3.43 [2.40; 4.89] p<.001; RRR quitting in forties =5.25 [3.38; 8.14] p<.001; RRR quitting in fifties =4.48 [2.95; 6.79] p<.001), to relapse (RRR Relapse =3.66 [2.82; 4.76] p<.001) and to be persistent smokers (RRR persistent =5.25 [3.81; 7.25] p<.001) compared to those who had initiated smoking in young adulthood. These effects were particularly pronounced in case of ACEs. Smoking prevention programs aimed at reducing smoking initiation should be promoted to adolescents to limit the burden of smoking, especially for people who have suffered adversity during childhood.

Using linked administrative data to aid the handling of non-response and restore sample representativeness in cohort studies: the 1958 national child development study and hospital episode statistics data

BackgroundThere is growing interest in whether linked administrative data have the potential to aid analyses subject to missing data in cohort studies.MethodsUsing linked 1958 National Child Development Study (NCDS; British cohort born in 1958, n = 18,558) and Hospital Episode Statistics (HES) data, we applied a LASSO variable selection approach to identify HES variables which are predictive of non-response at the age 55 sweep of NCDS. We then included these variables as auxiliary variables in multiple imputation (MI) analyses to explore the extent to which they helped restore sample representativeness of the respondents together with the imputed non-respondents in terms of early life variables (father’s social class at birth, cognitive ability at age 7) and relative to external population benchmarks (educational qualifications and marital status at age 55).ResultsWe identified 10 HES variables that were predictive of non-response at age 55 in NCDS. For example, cohort members who had been treated for adult mental illness had more than 70% greater odds of bring non-respondents (odds ratio 1.73; 95% confidence interval 1.17, 2.51). Inclusion of these HES variables in MI analyses only helped to restore sample representativeness to a limited extent. Furthermore, there was essentially no additional gain in sample representativeness relative to analyses using only previously identified survey predictors of non-response (i.e. NCDS rather than HES variables).ConclusionsInclusion of HES variables only aided missing data handling in NCDS to a limited extent. However, these findings may not generalise to other analyses, cohorts or linked administrative datasets. This work provides a demonstration of the use of linked administrative data for the handling of missing cohort data which we hope will act as template for others.

Large Language Models for Epidemiological Research via Automated Machine Learning: Case Study Using Data From the British National Child Development Study.

Large language models have had a huge impact on natural language processing (NLP) in recent years. However, their application in epidemiological research is still limited to the analysis of electronic health records and social media data. To demonstrate the potential of NLP beyond these domains, we aimed to develop prediction models based on texts collected from an epidemiological cohort and compare their performance to classical regression methods. We used data from the British National Child Development Study, where 10,567 children aged 11 years wrote essays about how they imagined themselves as 25-year-olds. Overall, 15% of the data set was set aside as a test set for performance evaluation. Pretrained language models were fine-tuned using AutoTrain (Hugging Face) to predict current reading comprehension score (range: 0-35) and future BMI and physical activity (active vs inactive) at the age of 33 years. We then compared their predictive performance (accuracy or discrimination) with linear and logistic regression models, including demographic and lifestyle factors of the parents and children from birth to the age of 11 years as predictors. NLP clearly outperformed linear regression when predicting reading comprehension scores (root mean square error: 3.89, 95% CI 3.74-4.05 for NLP vs 4.14, 95% CI 3.98-4.30 and 5.41, 95% CI 5.23-5.58 for regression models with and without general ability score as a predictor, respectively). Predictive performance for physical activity was similarly poor for the 2 methods (area under the receiver operating characteristic curve: 0.55, 95% CI 0.52-0.60 for both) but was slightly better than random assignment, whereas linear regression clearly outperformed the NLP approach when predicting BMI (root mean square error: 4.38, 95% CI 4.02-4.74 for NLP vs 3.85, 95% CI 3.54-4.16 for regression). The NLP approach did not perform better than simply assigning the mean BMI from the training set as a predictor. Our study demonstrated the potential of using large language models on text collected from epidemiological studies. The performance of the approach appeared to depend on how directly the topic of the text was related to the outcome. Open-ended questions specifically designed to capture certain health concepts and lived experiences in combination with NLP methods should receive more attention in future epidemiological studies.

Depression Earlier on in Life Predicts Frailty at 50 Years: Evidence from the 1958 British Birth Cohort Study.

Frailty and depression in older ages have a bidirectional relationship, sharing some symptoms and characteristics. Most evidence for this has come from cross-sectional studies, or longitudinal studies with limited follow-up periods. We used data from the National Child Development Study (1958 Birth Cohort) to investigate the relationship between depression and early-onset frailty using a life course perspective. The primary outcome was frailty based on a 30-item inventory of physical health conditions, activities of daily living and cognitive function at 50 years. The main exposure was depression (based on a nine-item Malaise score ≥ 4) measured at 23, 33 and 42 years. We investigated this relationship using multiple logistic regression models adjusted for socio-demographic factors, early life circumstances and health behaviours. In fully adjusted models, when modelled separately, depression at each timepoint was associated with around twice the odds of frailty. An accumulated depression score showed increases in the odds of frailty with each unit increase (once: OR 1.92, 95%CI 1.65, 2.23; twice OR 2.33, 95%CI 1.85, 2.94; thrice: OR 2.95, 95%CI 2.11, 4.11). The public health significance of this finding is that it shows the potential to reduce the physical burden of disease later in life by paying attention to mental health at younger ages.

Effects of absolute levels of neighbourhood ethnic diversity vs. changes in neighbourhood diversity on prejudice: Moderation by individual differences in personality

This paper examines drivers of prejudicial attitudes among adults in the UK, focusing on the interaction between ethnic out-group size and personality traits. Leveraging data from the National Child Development Study (NCDS), we use two survey waves carried out in 2000 and 2008, just before and after the EU enlargement policy that drove a wave of immigration in the UK. We test the extent to which personality traits moderate the relationship between both absolute levels and changes in ethnic diversity at the local level, respectively, and prejudice. Key findings suggest that personality traits, in particular one's agreeableness, are important for conditioning how the proportion of non-white British in one's neighbourhood affects out-group attitudes. We observe a tendency towards polarisation in prejudicial attitudes between low-/high-agreeableness residents as their neighbourhoods become more diverse. These findings have important implications for theorising how contextual and individual characteristics jointly affect intergroup relations.

Labour force transitions and changes in quality of life at age 50–55 years: evidence from a birth cohort study

Abstract In the context of an ageing population and longer working lives, the impact of increasing rates of early exit from the labour force on quality of life is a particularly current concern. However, relatively little is known about the impact on quality of life of later-life labour force transitions and various forms of early exit from the labour force, compared to remaining in employment. This paper examines lifecourse labour force trajectories and transitions in relation to change in quality of life prior to the State Pension Age. Lifecourse data on early life circumstances, labour force trajectories and labour force transitions from 3,894 women and 3,528 men in the National Child Development Study (1958 British Birth Cohort) were examined in relation to change in quality of life, measured by a short-form version of CASP, between the ages of 50 and 55. Women and men differed in the types of labour force transition associated with positive change in quality of life, with men more frequent beneficiaries. For both men and women, labour force exit due to being sick or disabled was associated with a negative change in quality of life, whereas joining the labour force was associated with a positive change in quality of life. Moving into retirement was associated with a positive change in men's quality of life, but not women's. Moving from full-time to part-time employment was associated with a positive change in women's quality of life but not men's. The findings that stand out for their policy relevance are: the threat to the quality of life of both women and men from early labour force exit due to limiting longstanding illness; and women are less likely to experience beneficial labour force exit in the later years of their working life, but are more likely to benefit from a reduction in working hours.

Adolescent development and the math gender gap

This paper investigates the determinants of the gap between girls and boys in mathematics performance (the ‘math gap’). We are particularly interested in the role played by pubertal development in explaining the widening of the math gap over adolescence. We estimate rich production function models of math skills, using data from the 1958 British National Child Development Study (NCDS), a longitudinal survey of all British children born in a single week in March 1958 which contains unique information on pubertal development and educational outcomes. Using (cumulative) value-added models, we show that the impact of puberty varies by the age and gender of the child, and that this heterogeneity can explain about two thirds of the math gap that emerges between the ages of 11 and 16. We find also that the widening of the math gap during adolescence is driven by markers of pubertal development which are publicly evident, rather than by markers which are only privately evident; and that the relationship between puberty and math scores is strongly associated with children's self-perceived ability in math. Taken together, these results suggest that the mechanisms underlying the relationship between pubertal development and the math gender gap are socially rather than biologically driven.

Mentally-passive sedentary behavior and incident depression: Mediation by inflammatory markers

BackgroundSedentary behavior (SB; time spent sitting, as distinct from lack of exercise or physical activity) is associated with depression, yet little is known about the relationship between different types of SB (e.g., mentally-passive versus mentally-active) with depression and potential biological mediators of these associations. MethodsWe used cohort data from the 1958 National Child Development Study (n = 4607; 50.4 % women), conducted in UK, employing the 44 y and 46 y waves as baseline, and the 50 y and 55 y waves as follow-up. Participants reported time spent in TV viewing and watching videos (mentally-passive SB); and, time sitting while doing light activities such as deskwork or driving a car during worktime (mentally-active SB). Depression diagnosis was self-reported during the initial and follow-up waves. Waist circumference, C-reactive protein, and glycated hemoglobin were examined as potential mediators. ResultsMentally-passive SB was associated with incident depression (HR: 1.43; 95%CI: 1.19; 1.71), while there was no association for mentally-active SB. Waist circumference (coefficient: −0.03; 95%CI: −0.05; −0.01; 9.2 %) and C-reactive protein (coefficient: −0.03; 95%CI: −0.04; −0.01; 8.3 %), but not glycated hemoglobin, partly mediated the association for mentally-passive SB. ConclusionsIn the relationship of mentally-passive SB with incident depression, the mediating contributions of waist circumference and C-reactive protein point to possible inflammatory-related mechanisms.