Early life adversity and life course health: an investigation of adversity clustering and associations with health

Early life adversities, such as child maltreatment, are all too common in the UK. Research to date suggests that such adversities can have long-term effects on health. For instance, adversities experienced in childhood and even during pregnancy may alter the way the body deals with stress throughout life. This can result in an increased risk of diseases such as heart disease, depression and type 2 diabetes. It is therefore important to investigate how early life adversities might be linked to poorer health to better inform the development of interventions. Previous research into the health effects of early life adversities has been limited in a number of ways. Firstly, many studies have added up the number of adversities a child has experienced to create a score indicating 'total stress'. Unfortunately many children who experience one adversity are also more likely to experience another. The approach of tallying adversities does not help us to understand how adversities might affect health and what we can do about this. We also don't know whether experiencing adversities at certain ages (e.g. during pregnancy) has a greater effect on health than when experienced at other points in early life. There is also little evidence on whether associations between early life adversities and health are different for boys and girls. Also different types of early life adversity are likely to have different associations with health. The aim of this project is to develop a more valid measure of early life adversity and investigate how it is related to health at different points of life. This new measure will take account of the way in which children who experience one adversity are more likely to experience another. This measure will then be applied to look at associations with health. The research will focus on mental health from childhood onwards, as well as biological markers of stress from childhood and into adulthood. The research will use three of the UK's world-renowned longitudinal studies: the Millennium Cohort Study (MCS), Avon Longitudinal Study of Parents and Children (ALSPAC), and National Child Development Study (NCDS). These are all large studies with >15,000 participants. Each study has followed the same group of people over time. ALSPAC will be used to assess associations between early life adversities in relation to biological markers of stress from childhood into adolescence. The MCS will be used to assess whether children who experience early life adversities are more likely to have mental health problems across childhood and into adolescence. Finally, the NCDS will be used to test associations between early life adversities and both biological markers of stress in middle-age and mental health across adulthood. The proposed project will be undertaken at the Department of Epidemiology and Public Health at UCL under the mentorship of Prof. Yvonne Kelly, with support from a network of experts in social statistics, biology and sociology in the International Centre for Life Course Studies in Society and Health. Non-academic partners will be involved from the beginning of the research process. These partners include Barnardo's, the Association of Young People's Health and the Department of Health, who will be able to feed the findings of the research into their work with vulnerable families. Outputs from the project will include at least six academic papers, presentations at six conferences, a briefing note for non-academic audiences, an end of project policy seminar for academics and non-academics, and contributions to blogs and Twitter. The project also has a strong training element to enable the principal investigator to make the transition to independent researcher. In summary, this project has the potential to advance research in the field of early life adversities and health. It will be the first to provide evidence on how early life adversities increase the risk of poor health.