Alcohol is one of the most widely consumed drugs globally. A body of evidence suggests a link between underage alcohol consumption and an increased risk of depressive disorders; however, the direction of causality is unknown. Previous research has mostly focused on how mental health induces drug use through self-medication; however, the inverse direction of causation is focused on in this investigation. To better understand and assess the magnitude of this link, we focused on whether regular alcohol consumption between the ages of 15 and 18 is associated with eventual depressive symptoms in the mid-20s. This association will be facilitated by a cohort study that uses questionnaires and self-report measures to follow individuals over a 30 year period.

Attachment style theory by Bowlby (1962) states that infants have a primary goal to bond with and maintain proximity to their caregiver, which evolved for survival purposes. Ainsworth later identified four attachment styles: secure, avoidant, anxious and disorganised attachment styles. These attachment styles formed in childhood were suggested to be associated with one’s future emotional and social development, communications and interpersonal relationships in adulthood. This study aims to examine whether attachment styles at age 3 predict an individual's well-being at age 23.

Previous evidence has shown that starting your period at an earlier age may increase your risk of having complications during pregnancy, such as a low birth weight baby. However, this evidence was all based on observations which may be skewed by the fact that having a higher BMI makes you more likely to start periods earlier and also increases your risk of these pregnancy complications. We will estimate the effect of having an earlier period on your risk of having complications during pregnancy association within ALSPAC. We will account for factors such as BMI and smoking, which have been collected in great detail for the volunteers participating in ALSPAC. This will then be compared to a separate approach to answer the same question, using a method called Mendelian randomization.

Although there are several UK studies that consider the impacts of attending youth clubs on later life (e.g. Dibben, Playford and Mitchell 2017 and Berrie et al 2022), little longitudinal research has taken place in the UK, leaving a shortfall of robust evidence. Using data from four longitudinal cohort studies (ALSPAC, the British Cohort Study, Next Steps Generational Study, the Millennium Cohort Study) and Understanding Society (the UK household longitudinal study), this project will analyse the extent to which attendance of voluntary out-of-school youth provision has effects over time on: a) educational and career pathways; b) physical health; c) mental health; d) emotional development and mental wellbeing; e) tendency towards anti-social behaviour. The analysis will control for relevant characteristics, allowing for isolation of the impact that involvement in youth activities generates for young people. It will examine the effects on these young people at the time of their involvement, and afterwards, up until they are 30 years old. Additionally, the analysis will shed light on the existence of any systematic differences between participants and non-participants of youth activities.

In this study we aim to analyse whether or not vitamin D levels during pregnancy influence lung development and, consequently, the occurrence of asthma and lung function performance in childhood and adolescence. To analyse these associations, we will use two methodologies. First, we will look at whether or not vitamin D levels measured in blood during pregnancy are associated with the onset of asthma and lung function parameters at 8-9 years and 15-16 years in the ALSPAC cohort. Since this association may be influenced by many confounding factors such as lifestyle, socio-economic status, the season of the year when the blood was obtained, we will use Mendelian Randomisation to overcome this limitation. We will analyse whether or not genetic variants that predispose to having low levels of vitamin D are associated with a greater predisposition to having asthma and poorer lung function in childhood and adolescence. We will use data from 4 different European cohorts and one Australian cohort and, after doing all the analysis separately, we will collect the results and do a meta-analysis using all data.

Key to causal inference from observational data is adequate adjustment for confounders (i.e., factors which cause both the exposure and outcome). However, knowing whether a variable is a confounder (requiring statistical adjustment) or a mediator (i.e., a variable caused by the exposure which in turn causes the outcome; not requiring statistical adjustment) is often difficult to establish with certainty and often relies upon potentially-debatable assumptions. By making use of the repeated data collected by ALSPAC - both in terms of religiosity and data on other covariates which may be plausible confounders and/or mediators - it is possible to make reasonable inferences as to whether religiosity causes the covariate, the covariate causes religiosity, or indeed whether there is bidirectional causation (i.e., religiosity causes the covariate and the covariate also causes religiosity). If data permit adjustment for baseline confounders, prior exposure and prior outcomes, then it may be possible to infer causality using longitudinal observational data (VanderWeele 2021; VanderWeele et al., 2016). We intend to apply these methods in ALSPAC to explore potential bidirectional causation between religiosity and a range of covariates to better understand these patterns and to help inform future work using these data.

References:
VanderWeele, T. J. (2021). Can sophisticated study designs with regression analyses of observational data provide causal inferences?. JAMA psychiatry, 78(3), 244-246.
VanderWeele, T. J., Jackson, J. W., & Li, S. (2016). Causal inference and longitudinal data: a case study of religion and mental health. Social psychiatry and psychiatric epidemiology, 51(11), 1457-1466.

Sustainable diets are linked to co-benefits for human and planetary health, such as decreased environmental impacts by reducing carbon dioxide emissions and improved cardiometabolic health. However, the applicability of sustainable diets to obtain co-benefits has been investigated in adults but not for children and adolescents, who have unique nutritional requirements. To address this, co-benefits of sustainable diets will be estimated in children in ALSPAC. Specifically, we will assess the environmental impacts from diets (e.g., carbon dioxide, water usage, and biodiversity) in children from ALSPAC and associated cardiometabolic health parameters (e.g., body mass index) and estimate the reduction of environmental impacts from switching to a more sustainable diet (e.g., EAT-Lancet reference diet). Uniquely, this project will have in depth assessment of associated co-benefits from reducing ultra-processed foods, a topic of much debate in terms of their true environmental impact. Results from this study can be used to inform sustainable dietary targets specific for children and adolescents and associated policies in the United Kingdom.

Research has shown that adults who look back on their childhood and say that they had a positive relationship with their parents, or felt loved by their parents, have better mental health. Indeed, these emotional memories can be more important for mental health than memories of specific behaviours that parents engaged in. However, we don’t know how the relationship between feeling loved in childhood and mental health actually comes about.
In this study, we will firstly look at how genetics relates to people saying they felt loved in childhood. People who took part in a large research study answered a question about whether they felt loved in childhood and provided a blood sample, so that we can look at their genetics. Genetic material (DNA) is made up of millions of tiny units called base pairs. At each base pair, a person can have one of two alleles. We will look at whether the allele that a person has at each base pair increases or decreases their likelihood of reporting that they felt loved in childhood. We will then look at whether there are similarities in how genetics contributes to feeling loved in childhood and depression, anxiety, and wellbeing.
This will help us to understand some of the reasons people are more or less likely to say they felt loved in childhood. It can also provide a better understanding of how feeling loved in childhood relates to mental health. All of this is important for how we understand the causes of mental health problems.

We have identified a proteomic pattern in serum from a major fraction of pediatric cancer patients that we do not see in healthy controls and only occasionally in adult patients. We suspect this pattern is associated with a risk of cancer rather than being a consequence of the disease, and for this purpose we are searching for biobanks with blood samples from healthy children who later contracted cancer, to see if the pattern can be identified before cancer appears.