Title: Accumulative processes in health inequalities: the socioeconomic causes and consequences of mental and physical health comorbidity in adolescence
Funder: Economic and Social Research Council

Abstract: There are a number of guiding objectives to the research project: PRIMARY RESEARCH OBJECTIVES 1. Analyse and understand how early-life circumstances and experiences influence the comorbidity of depressive symptoms and high BMI in adolescence 2. Provide empirical evidence on whether depressive symptoms and body mass index (BMI) together predict educational achievement, aspirations and later socioeconomic attainment BROADER ACADEMIC OBJECTIVES 1. Advance the application and testing of cumulative (dis)advantage theory in health inequalities 2. Bring together evidence from different disciplines and strengthen links between academics in different disciplinary fields studying social and health disadvantage 3. Use and propagate advanced methods in longitudinal data analysis 4. Develop the application of genetic instrumental variable methods (i.e. Mendelian Randomisation, MR) in social sciences SKILLS DEVELOPMENT OBJECTIVES 1. Develop my skills in leadership and project management to become a leading investigator on the intersection of health and social inequalities 2. Advance my skills in innovative statistical methods in life course research 3. Build and consolidate international and interdisciplinary research networks and collaborations PUBLIC AND POLICY ENGAGEMENT OBJECTIVES 1. Cultivate links with stakeholders in third-sector organisations and health and social services to discuss research directions and priorities 2. Disseminate research findings that help identify risk factors for mental and physical health comorbidity and accumulating disadvantage in adolescence 3. Engage policy-makers across government with the evidence base to improve adolescent health and wellbeing and address social mobility and inequality

Lay abstract: The research project investigates accumulative inequalities in health and social outcomes through investigating the causes and consequences of the comorbidity of depressive symptoms and high body mass index (BMI) in adolescence. Rates of high BMI such as being overweight or obese have been increasing in children in many economically developed countries including the UK, and there has been widespread concern that mental health problems such as depression have also been on the rise. These important aspects of adolescent wellbeing often co-occur and can develop together. They are also associated with numerous childhood social factors such as family socioeconomic circumstances and experiencing negative life events. Importantly, adolescent health and wellbeing can in turn influence school achievement and later socioeconomic opportunities. The strong links between depressive symptoms and BMI indicate that mental and physical health problems may accumulate, which can have even greater consequences than difficulties in any specific area of health or wellbeing on their own. In this research project, I will use two longitudinal studies on adolescents and one large genetically informed cross-sectional study of adults to understand how inequalities develop. The theoretical framework of the project is based on accumulative (dis)advantage theory, which suggests that disadvantage in different areas of life may interact with consequences bigger than the sum of its parts. The analyses apply advanced statistical methods to characterise the relationship between depressive symptoms and BMI across adolescence, the social predictors of their comorbidity, and to estimate the strength of their effects on later outcomes. The project addresses the following research questions: - How do early-life socioeconomic circumstances predict the comorbidity of depressive symptoms and high BMI in adolescence? - Does the number and severity of adverse life events in childhood predict the comorbidity and explain some of the influence of family background? - Have there been cohort changes in the social determinants and gender-specific patterns of comorbid depressive symptoms and high BMI? - Do depressive symptoms and high BMI interact to impact school grades and educational aspirations? - Do depressive symptoms and high BMI together predict education, income and living with a spouse in adulthood more strongly than either separately? The project will study the interaction of depressive symptoms, BMI and social circumstances with an interdisciplinary approach, because of the close links between health and social factors and the potential contribution to knowledge in a range of disciplines. Undertaking the project will further my development into an independent academic and enable me to build impactful connections with policy-makers and stakeholders. Advancing our understanding of the early drivers of accumulative disadvantage and the benefits of early investments to wellbeing, the project will be useful for policy-makers in a wide range of policy areas and professionals in health and social services aiming to improve adolescent wellbeing and, ultimately, to address inequalities in life chances.

Research activity codes: 2.4 SURVEILLANCE AND DISTRIBUTION
Health categories: GENERIC HEALTH RELEVANCE