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.

Menopausal symptoms affect around 70% of women as they go through the menopause, but we don't know very much about what causes the various symptoms. It is not clear how different symptoms might be linked and who is at risk of developing them. We will use genomics to find the causes of a range of menopausal symptoms, including; hot flushes, sleep disturbance, mood changes and sexual dysfunction. We will develop a questionnaire to distribute to study participants to collect information about their symptoms and combine this with genomic data previously collected.

We aim to explore the associations between adverse childhood events (ACEs) and weight trajectory (diet change, alcohol consumption, and change in physical activity) amongst the G0 Mothers in ALSPAC. Also investigating whether religious beliefs and behaviours (and changes thereof) moderate this relationship and whether depression score mediates this relationship. In these analyses we will adjust for relevant confounders such as demographic characteristics, smoking status, and age.

Information can be obtained from ALSPAC (B number folder) or the UK LLC on request

Physical activity (PA) during pregnancy reduces the risk of gestational diabetes mellitus (GDM) and excessive weight gain. DNA methylation (DNAm) - changes to DNA sequence but not the structure - is a potential molecular mechanism through which physical activity (PA) mediates the effects on the transcriptome. Original discovery analyses were run in a cohort from Norway (EPIPREG) and we want to replicate their findings to see if these CpG sites are associated with PA.

The aim of the project is to look at foods and food group choices in school meals and snacks by children aged 13 years who were persistent picky eaters in the early years. The data were collected via questionnaires that the children completed themselves. Children with persistent picky eating habits during their early years have already been identified. Their choices will be compared with those of children who were not picky eaters.

Childhood maltreatment has a profound impact on both the short- and long-term wellbeing of children. Specifically, children with autism and those with attention deficit/hyperactivity disorder have a higher risk to experience maltreatment than those with typical development. However, the reasons why this is happening, are unclear. Two studies will be conducted. The first study will investigate the relationship between childhood maltreatment and ADHD. Studies support an association between ADHD and maltreatment: Children with ADHD have higher risk of experience maltreatment than those without ADHD, as well as people who suffered childhood maltreatment have high levels of ADHD symptoms and diagnosis. Also, parental ADHD and/or experience of maltreatment could influence the strength of this association. So, we will define and analyse how genetic and social factors affect the association between ADHD and childhood maltreatment, and then how this could be developed through generations. Having assessed and display the association between ADHD and childhood maltreatment, the second study will go a step forward searching the experience of physical abuse and harsh parenting in children with ADHD and children with autism. We will conduct a comparison between children with ADHD and children with autism trying to understand how the different traits of each condition may affect different the risk of physical abuse and harsh parenting.

Religion is an important suite of beliefs and behaviours, yet the factors which cause religious beliefs and behaviours are still largely unknown. One such factor believed to shape religion is intelligence, with previous meta-analyses suggesting a negative association between measures of intelligence and religious belief (Zuckerman et al., 2020). However, the majority of this previous research has been cross-sectional and focused predominantly on American undergraduates, meaning results may be biased by confounding and/or not generalisable to the wider population. We therefore need longitudinal data from population-based studies with repeated religiosity and intelligence data to assess whether these associations may be causal in a more representative population. Enter ALSPAC.

References:
Zuckerman, M., Li, C., Lin, S. & Hall, J.A. (2020). The Negative Intelligence–Religiosity Relation: New and Confirming Evidence. Personal. Soc. Psychol. Bull., 46, 856–868.

Suicide is a leading cause of death among youth, but little is known about the associated risk factors. Growing recognition that the existing clinical and psychological measures do not predict suicidal behaviour very strongly has contributed to a focus on the genetic correlates and predictors of suicide risk. Although genotypes do not change across the lifespan, an epigenetic process known as DNA methylation is responsive to environmental experience and can modify the expression of certain genes. Although numerous investigations have cross-sectionally identified a role for DNA methylation changes in self-injurious thoughts and behaviours (such as suicide attempt, suicidal thoughts, and self-injury without suicidal intent), these studies have largely focused on adults. Given that development is associated with numerous biological, epigenetic, and psychosocial changes, there is a need to better identify specific DNA methylation risk factors in youth, rather than extrapolating from work in adults. In this project, we aim to conduct epigenome-wide association studies (case-control comparison of methylation at numerous locations in the genome) of suicide ideation; suicide attempt history; and self-injury without suicidal intent; in teenagers who are part of the Avon Longitudinal Study of Parents and Children. We will also be able to make use of methylation measurements taken in childhood and at birth to trace any methylation differences backward, in an attempt to understand when they might emerge. These findings will be essential to identifying youth-specific risk factors for suicide, and ultimately contribute to efforts to better inform risk assessment as well as biologically informed interventions.