Session 4 abstracts

Track 1 - Symposium: Genetics Research in the Millennium Cohort Study

The MCS Genetics Data Resource
Study: Millennium Cohort Study

Gemma Shireby, UCL Centre for Longitudinal Studies

This presentation will provide an overview of the genetics data in the Millennium Cohort Study (MCS), including the recent construction of an imputed and quality controlled genotypic dataset of trios of MCS cohort members and their parents. The data have several attractions, including facilitating the detection of parent-of-origin effects. The presentation will also provide an overview of the genetics data available in two other birth cohort studies managed by CLS: the 1958 National Childhood Development Study (NCDS) and the 1970 British Cohort Study (BCS70). Finally, it will discuss work to generate polygenic risk scores for a range of traits in the cohorts that researchers will be able to utilise. Together, these genetic data have the potential to uncover how genetic and environmental factors shape human development over the life course and across historical periods.

Changing Polygenic Penetrance on Childhood and Adolescent Body Mass Index: A Cross-Cohort Analysis of Two British Birth Cohort Studies
Study: Millennium Cohort Study

Liam Wright, UCL Centre for Longitudinal Studies

While obesity is a highly heritable trait, obesity rates have more than doubled in the UK since the 1980s, demonstrating a clear impact of the environment on body mass index (BMI). However, BMI has not risen uniformly across the population; individuals appear to differ in susceptibility to environmental causes of high BMI. In this study, we examine the changing role of genetics by exploring associations between polygenic risk for BMI and obesity in two British birth cohort studies spanning the years 1946-2018 (the NSHD and the MCS).

Genetic associations with parental investment from conception to wealth inheritance in six cohorts
Study: Millennium Cohort Study

Jasmin Wertz, University of Edinburgh

Genetic inheritance is not the only way parents’ genes may impact children. It is also possible that parents’ genes are associated with investments into children’s development. We tested links between parental genetics and parental investments, from the prenatal period through to adulthood, using data from six population-based cohorts, including the MCS. Findings revealed widespread associations between parental genetics — summarised in a genome-wide polygenic score — and parental behaviour across development, including smoking in pregnancy and leaving wealth to adult children. Effect sizes were small at any given time point, but there was evidence for accumulating effects across development.

Track 2 - Mental health

Time trends in mental health trajectories across childhood and adolescence, findings from two UK cohorts
Studies: Millennium Cohort Study & ALSPAC

Jessica Armitage, Cardiff University

Co-authors: Foteini Tseliou, Alex Kwong, Ruth Sellers, Rachel Blakey, Rebecca Anthony, Frances Rice, Anita Thapar and Stephan Collishaw

Over the past three decades, epidemiological studies have documented rises in emotional problems for individuals born more recently. These increases have tended to be more prominent for adolescents compared to younger children, however, no study has directly tested secular trends in emotional problems across development. In this presentation, I discuss the findings from a study that used data from two longitudinal population-based cohorts born ten years apart; the Avon Longitudinal Study of Parents and Children (ALSPAC) and the Millennium Cohort Study (MCS), to assess for the first time, whether emotional problem trajectories have changed over time in the UK.

Sexuality-related inequalities in the prevalence and impact of adverse childhood experiences on health in late adolescence – A national longitudinal cohort study
Study: Millennium Cohort Study

Rahul Chandrasekar, University College London

Co-authors: Amal R. Khanolkar and Alexis Karamanos

This study used information on 9 ACEs collected prospectively in childhood alongside self-reported sexuality and outcomes, including a range of mental/general health and health-risk behaviours (HRBs), assessed at age 17 years (N=8686, from the MCS). Associations between sexuality and individual/total ACE scores were assessed using multinomial logistic regression, while associations between total ACE scores and each outcome were analysed using multivariable linear/logistic regression (including interaction terms between ACE and sexuality variables). We found that SM individuals experienced greater bullying and overall ACE accumulation. However, the differential impact of ACEs on health in SM individuals was limited to certain indicators of internalising and externalising mental health, and we found no evidence for a differential impact on HRBs.

The impact of sexual violence in mid-adolescence on mental health
Study: Millennium Cohort Study

Praveetha Patalay, UCL Centre for Longitudinal Studies

Co-authors: Francesca Bentivegna

A large gender gap appears in internalising mental health during adolescence. Sexual violence experiences are disproportionately experienced by females. There is little high-quality longitudinal population-based research investigating the role of sexual violence experiences at this age on mental health outcomes and the mental health  gender gap. This study aimed to estimate the mental health impact of sexual violence experiences (harassment, assault) in mid-adolescence on key mental health outcomes (psychological distress, self-harm and attempted suicide) amongst girls and boys using data from the UK Millennium Cohort Study.

Track 3 - Weight inequalities and mental health

Impact of adverse childhood experiences on mental ill-health and obesity comorbidity in adolescence – A national longitudinal cohort study
Study: Millennium Cohort Study

Alexis Karamanos, King’s College London and Amal Khanolkar, King’s College London

Mental health (MH) problems (depression/anxiety) and obesity are increasing in prevalence in childhood and both conditions are likely to co-occur. Less in known about the association between adverse childhood experiences (ACEs) and mental ill-health and obesity comorbidity (MH-OB) in adolescence in the UK.

This study examined associations between six ACEs (e.g., parental MH, maternal drug and alcohol misuse, bullying) collected prospectively across childhood at 3, 5, 7 and 11 years and MH-OB comorbidity at ages 14 and 17. Data were from the Millennium Cohort Study (N=10,734, males=50.3%).

Association of childhood weight trajectory and depressive symptoms at 17 years: Exploring the mediating role of body dissatisfaction in the UK Millennium Cohort Study
Study: Millennium Cohort Study

Madelaine Davies Kellock, University College London

Co-authors: Yvonne Kelly, Anne McMunn and Francesca Solmi

We use Millennium Cohort Study data to model the extent to which body dissatisfaction in mid-adolescence mediates the association between childhood weight trajectory and depressive symptoms in later adolescence. As BMI can be elevated due to increased muscle mass, we look at both BMI and a measure of adiposity, using counterfactual mediation analysis to account for other potential pathways from weight to depression. We find that evidence of partial mediation, suggesting that interventions to improve body dissatisfaction could reduce depressive symptoms in later adolescence.

Understanding socioeconomic inequalities in body mass index and body composition through interactions between internalising/externalising symptoms and environmental conditions
Study: Millennium Cohort Study

Charis Bridger Staatz, UCL Centre for Longitudinal Studies

Co-authors: Yvonne Kelly, Rebecca E Lacey and Rebecca Hardy

Previous studies have linked both adolescent mental health, such as internalising and externalising symptoms, and environmental conditions, such as fast-food density and green spaces, to inequalities in obesity over the life course. However, few studies have explored interactions between the two when considering inequalities in adiposity. Therefore, this study aimed to assess if internalising and externalising symptoms mediate associations between socioeconomic position (SEP) and adiposity among adolescents and explored if the strength of the mediating paths is influenced by characteristics of the environment.