Numerous studies have shed light on the effects of maternal smoking during pregnancy on the offsprings’ health outcomes. In particular, maternal smoking during pregnancy was found to be associated with lower offspring birthweight. Previous studies normally address confounding by adjusting for maternal age, socioeconomic status, breastfeeding and offspring gender. However, concerns about unmeasured confounding biases due to the mother’s lifestyle, the households’ socioeconomic status, and mother’s genotypes still remain.

The negative control method is a recently popularized approach that utilizes measured covariates as proxies of unmeasured confounders, in order to detect, reduce and correct for confounding bias. This method may help eliminate the confounding bias when studying the causal effect of maternal smoking on child birth weight. For example, paternal alcohol consumption during the mother’s pregnancy can serve as a potential negative control variable since it’s a proxy of the household’s socioeconomic status but shouldn’t directly affect the offspring’s birth weight. Therefore, any observed association between paternal alcohol consumption and the child’s birth weight is likely a result of confounding bias. Other negative control variables may include negative control exposures (NCEs) such as mother’s smoking behavior after giving birth, and negative control outcomes (NCOs) such as the child’s injuries since age 9.

In this project, we will utilize multiple negative control variables to obtain a more accurate estimate of the causal effect of maternal smoking during pregnancy on infants’ birthweight with the ALSPAC data.

Cancer is a leading cause of morbidity and mortality worldwide. Its burden is expected to increase in the coming years as populations age and increase their exposure to unhealthy lifestyle factors. Most research on cancer aetiology has been conducted in adult populations. This has led to the identification of well-established risk factors in adulthood, such as smoking and obesity. Nevertheless, it is still unclear whether cancer risk may be influenced by early life exposures. Furthermore, the mechanisms by which early life exposures may influence cancer risk have not been fully elucidated. They possibly involve inflammation, changes in the microbiome, metabolism, insulin resistance, hormonal factors and epigenetic modifications. Therefore, the aim of this project will be to identify novel early life risk factors and molecular markers for the prevention of cancer.

This project will investigate the relationship between gratitude and meaning in life. There is a large body of evidence demonstrating a positive association between gratitude and wellbeing (Sansone & Sansone, 2010; Wood et al., 2010). However, research into the relationship between gratitude and specific aspects of wellbeing, namely eudaimonic wellbeing, is lacking. Eudaimonic wellbeing refers to the extent to which someone is fully functioning, focusing on meaning and self-realisation (Ryan & Deci, 2001). Meaning in life is a key indicator of eudaimonic wellbeing, therefore by investigating the predictive relationship between gratitude and meaning in life, this study will enable insights into the relationship between gratitude and eudaimonic wellbeing. In addition, this study aims to investigate whether the relationship between gratitude and meaning in life is stronger in some individuals than others, such that this study will investigate the moderating role of gender, qualification, and childhood socioeconomic status. The potential moderating role of these variables will be investigated because there is evidence suggesting that gender moderates the willingness to express gratitude, with men being less likely to feel and express gratitude than women (Kashdan et al., 2009). Additionally, there is evidence that measures of childhood socioeconomic status are associated with wellbeing, with more disadvantaged childhood socioeconomic status being associated with worse mental wellbeing at middle-age (Wood et al., 2021). Finally, there is mixed evidence regarding the relationship between educational attainment and wellbeing (Nikolaev, 2018). Time permitting, this study will also explore how the relationship between gratitude and eudaimonic wellbeing differs to the relationship between gratitude and hedonic wellbeing. Hedonic wellbeing focuses on pleasure and happiness (Ryan & Deci, 2001), and will be measured by subjective happiness and life satisfaction. Overall, this study will provide implications for gratitude interventions, which are increasingly being advocated to improve wellbeing (Rash et al., 2011). This research will enable conclusions to be made regarding who is likely to receive the optimum benefit from gratitude interventions, based on the findings of the moderation analysis.

The project will investigate the impact that the transition to parenthood has on wellbeing. In particular, the project will focus on understanding how becoming a parent impacts individuals’ happiness, life satisfaction and meaning in life using a longitudinal design.
Research investigating the impact of parenthood on wellbeing produces mixed findings. Some findings indicate that parenthood is associated with detrimental effects on wellbeing (Stanca, 2012), whilst others have suggested that parenthood is associated with improved aspects of wellbeing (Nelson et al., 2013). However, the research investigating the effects of parenthood on wellbeing is difficult to summarise, due to the varying definitions of wellbeing that are used within the literature and the different means of operationalising the term. For example, studies have measured wellbeing by examining symptoms of depression, alcohol abuse, happiness, life satisfaction and frequency of positive and negative emotions. Therefore, this study aims to look at how parenthood effects different aspects of wellbeing individually as there may be differential effects of parenthood on happiness, life satisfaction, and meaning in life. Prior studies have found that parents have higher levels of meaning in life than non-parents (Nelson et al., 2013). However, there are more mixed findings regarding happiness and life satisfaction (Umberson & Gove, 1989). Therefore, the findings regarding the relationship between parenthood and wellbeing do not represent one construct and making concluding statements about parenthood and wellbeing would fail to acknowledge the discrepancies among how wellbeing has been measured and defined.
Previous research has suggested that the relationship between parenthood and wellbeing differs depending on gender, relationship status and financial strain on the parent. It has been reported that mothers experience poorer wellbeing in comparison to fathers (Nelson et al., 2019). Parents who are married may have better wellbeing in comparison to single parents because of the proposed benefits such as division of labour in the home and for parenting tasks (Cunningham & Knoester, 2007). Stanca (2012) also reported that parenthood negatively impacts life satisfaction due to a lack of financial satisfaction and increased financial strain associated with parenthood. Whether the individual is a first-time parent may also be important to investigate because experiences of parenting might not match prior expectations with consequences for mental health in new parents (Harwood et al., 2007).

This project will investigate the relationship between the Big 5 personality traits and social media usage of individuals in the ALSPAC cohort. The Five Factor Model of personality has been used extensively in psychology to predict attitudes and behaviour. The Big-Five personality traits act on a spectrum and consist of the following: Openness to Experience (characterised by one’s willingness to try new things as well as engage in imaginative and intellectual activities); Conscientiousness (associated with organisation, thoughtfulness and impulse control); Extroversion (characterised by the tendency and intensity to which someone seeks engagement with their environment); Agreeableness (concerned with how people tend to treat relationships with others) and Neuroticism: (associated with one’s overall emotional stability). With the recent rise in people using social media, there is growing interest in the association between personality and social media use. So far, this association has only been explored in US, Asian and Australian populations, with less focus on this association in a UK population. Further, past meta-analyses of the association between personality and social media use have arrived at different conclusions about which traits are associated with social media use and the effect size of these associations. This is likely due to varying definitions of social media use.
Current research has primarily focused on single platform use, but as the majority of people using social media use more than one platform, there is the need to investigate the relationship with multi-platform use. Most studies examining the relationship between social media use and the Big Five personality traits have measured social media usage by using the most popular site, Facebook and a few studies have focused on general use of platforms. Understanding the link between personality and social media use is important because Neuroticism is associated with anxiety and depression, therefore it may be a confounding variable that future studies should take into account when exploring the association between multiple social media usage and anxiety/depression. There is also evidence of a link between multiple platform use and mental health difficulties, so it is important to understand the link between personality and social media use within the context of more than one social media platform. Taking this into consideration, this study aims to elucidate the associations between personality and social media use by concentrating on just a single definition of social media use (frequency of visits to a social media site) and examining this by focusing on one specific platform as well as multi-platform use of social media.
Exploratory analyses will also be run to examine potential moderators of the association between personality and social media use, such as gender and ethnicity, to help further explain the relationship.

Using existing dataset B3837
Children exposed to trauma during their early childhood are at a higher risk of early onset of mental disorders. Bereavement is one of the most prevalent adversities that children face. Empirical literature has highlighted child bereavement to be associated with lower emotional, behavioural, and social wellbeing during adolescence. Early to mid-adolescence is a critical developmental period for the onset and maintenance of psychopathology. A combination of personal attributes, family circumstances, and the nature of supportive networks outside the immediate family are found to be crucial for resilience when faced with early life trauma such as loss. Yet, little research has examined protective factors for children that have experienced bereavement and of those that have, there is limited understanding of the role of amenable maternal factors in improving mental health outcomes. Identifying modifiable maternal factors that may contribute to the development of resilience in children who have been exposed to childhood loss provides opportunity for early intervention. Therefore, the current study aims to examine whether modifiable maternal factors mediate the relationship between child bereavement and internalising or externalising problems during adolescence and early adulthood.

Depression is a complex and multifaceted disease, that will commonly onset during adolescence. Those who experience an episode during adolescence are much more likely to experience future episodes throughout adolescence and later adulthood. Equally, they are much more likely to experience deficits in educational attainment, social functioning, along with a greater likelihood of poorer physical and mental health (including co-morbidities with other psychiatric traits and substance misuse). The overarching aim of this project is to quantify the burden of adolescent depression using the prospective data from the Avon Longitudinal Study of Parents and Children (ALSPAC). As a society, it is important to establish any links between depressive symptoms in childhood/adolescence and later deficits in early adulthood in order to inform public policies. This will help identify those who are at higher risk of encountering particular physical, psychosocial or economic problems in early adulthood and to ensure the necessary resources are in place for support.

In the absence of hard CVD endpoints in the young, early structural changes within the heart and arteries - such as an increase in left ventricular mass or a thickening or stiffening of the major arteries - are often used in early prevention research as surrogate measures of early disease. Many studies have related changes in these phenotypes at a young age to increases in either BMI or body fat %, suggesting that excess adiposity at an early age may drive pathophysiological changes within the heart and vessels. Both of these are crude measures of adiposity, however, with the former unable to separate fat from lean mass, and the latter unable to quantify absolute levels of each tissue type. The extent to which these phenotypic changes are driven by fat mass per se rather than a combination of fat and lean mass remains equivocal.

Prenatal alcohol exposure (PAE) is a potent risk factor for depression, with several studies showing that moderate levels of PAE can more than double depression risk. However, the biological mechanisms linking alcohol exposure to long-term vulnerability for depression remain poorly understood. One possibility is that PAE reprograms the epigenome through DNA methylation (DNAm), epigenetic modifications that do not change the sequence of the genome, but can alter gene expression. Both animal and human studies suggest that PAE can induce lasting DNAm changes in the brain and periphery, including in blood and buccal epithelial cells, and that these DNAm profiles are associated with disease risk. Despite these known links between PAE, DNAm, and depression, there are three main gaps in the literature.

First, most human epigenetic studies are cross-sectional and cannot evaluate the causal links between PAE, epigenome-wide DNAm, and depression. As such, it remains unknown whether the relationship between PAE and depression is causal, requiring additional genetic and environmental analyses to parse this relationship.

Second, nearly all studies define PAE as any exposure to alcohol between conception and birth, despite recent evidence that the effects of early-life exposures may have vary depending on when they occur. As such, it remains unknown whether there are specific trimesters or sensitive periods when children are more vulnerable, PAE differentially affects DNAm patterns, and prevention efforts might be most effective.

Third, depression can manifest through different time-dependent patterns after its initial onset, varying with regards to symptom levels, recurrence, and length. Given that a single timepoint cannot fully capture this time-dependent variability, we recently harnessed repeated measures of depressive symptoms to characterize a set of unique depressive symptom trajectories across childhood and adolescence (Lussier 2020; Hawrilenko 2020). However, it remains unclear when and how prenatal risk factors, such as alcohol, influence the manifestation of depressive symptoms across development.

As such, we seek to extend our prior work, which focused on sensitive periods for childhood adversity, to further investigate the relationship between prenatal alcohol exposure, DNAm, and depressive symptom trajectories across development. The central hypothesis we will test is that PAE has causal and time-dependent influences on depression heterogeneity across development, with measurable effects on depressive symptom trajectories and epigenetic processes from age 4 to 24.