Temperament broadly refers to individual differences in behaviour that are typically measurable in infancy and early childhood. Broad dimensions include domains such as emotionality, negative affect, sociability and surgency. Measures typically capture a large number of individual subscales, as well as more general overall domains.

Fortunately, measurement of infant temperament has been developed over several decades, with considerable number of psychometric studies to support the measures and with an emphasis on capturing reliable individual differences. Commonly used scales include the infant temperament scales by Carey and the Infant–Toddler Social and Emotional Assessment by Carter and Briggs-Gowan.

Temperament and developmental milestones reflect early development of personality and behaviour. Infant temperament and milestones predict a variety of later outcomes in childhood.

Twin heritability for temperament domains has tended to be reported as between 30-40%. In general, this research field is characterised by smaller twin studies compared to studies of older ages. Some of the very large developmental twin cohorts of >5000 pairs (e.g. TEDS, CATSS) have either tended to begin main assessments after infancy or have included a small number of items in infancy.

Our study aims to explore the role of genetic variants on infant temperament and developmental milestones using a variety of state of the art statistical genetic methodology.

Loss of hearing is common, and tends to increase over the life course, affecting over 10 million people in the UK. Although there have been many studies concerning deafness in childhood, very few have examined the normal course and variation in hearing in a large population of individuals from an early age into mid and older adulthood. This is troubling since even low levels of hearing loss can result in failure to hear speech clearly, and can impact social communication, mental health and employment. Moreover hearing loss is associated with cognitive decline, and has been identified as one of the nine modifiable risk factors in the Lancet Commission on Dementia. It is not known whether hearing loss is a causal factor for cognitive decline, or a non-causal feature associated with ageing and neurodegeneration. Monitoring hearing in a population from early in life, and using novel genetic methods to investigate causality, may be crucial to understanding not just the role of hearing in cognitive function, but also the ageing process in general.

Utilising the Avon Longitudinal Study of Parents and Children (ALSPAC), this project will be the first to study, in depth, the changes in hearing ability over the life-course from early childhood to age 30 and to examine the relationship with cognitive function.

Firstly we will analyse data from approximately 5000 individuals, for whom we have detailed measures of hearing function at ages 7, 9, 11 and 14, and which we will collect again when they are age 30. We will characterise how their hearing has changed from age 7 to age 30, and identify those with who have experienced a drop in hearing ability. We will examine whether changes in hearing are associated with environmental exposures or the presence of particular genes.

Secondly we will analyse their cognitive function, using measures of memory, attention and processing speed collected at age 8, 10, 13, 15 and 24, and which we will collect again at age 30. We will compare trajectories in hearing ability with trajectories of cognitive function from age 7 to age 30, and test whether those who experience a decrease in their hearing ability are more likely to have poorer processing speed, attention and working memory at age 30.

The project is unique in that:
• it will provide observational information on the natural history and genetic influences on hearing over the first 30 years of life
• it will be the first to assess age-related relationships between changes in hearing and features of cognition through childhood into early adulthood

The information collected will be valuable for studies of further ageing of this population as well as identifying possible mechanisms linking hearing and cognition.

Childhood exposure to domestic violence is associated with long-term impairment such as increased risk of mental health illness, aggression, anti-social behaviour and poorer academic attainment, yet some children function well despite this adversity. As part of my doctoral thesis, I propose to use ALSPAC to identify the key factors which protect children and adolescents’ mental health following exposure to domestic violence. I will also examine whether or not the protective effect of these factors vary by socio-demographic and contextual factors (i.e. age, gender, socio-economic status, and severity/duration of domestic violence).

Resilience is the ability to bounce back and successfully adapt to challenging circumstances. It is not a personality trait and is amenable to change. Individual, family, and community protective factors that promote resilience in the face of childhood adversity have been identified within the literature . Studies that have explored protective factors within the contexts of domestic violence exposure and mental health outcomes have tended to explore single factors on their own, have not considered the complexity of the issue or contribution of other adversities, and have not necessarily considered the severity of the violence witnessed. Additionally, the vast majority of all research in the field has been conducted in the USA where attitudes towards violence and outcomes for both parents and children may differ to the UK. Therefore, more evidence is needed to identify how these factors protect against mental disorders in children who have been exposed to domestic violence. This research will provide an understanding of protective factors and their effects in different contexts will provide better information for the development of targeted interventions aimed at improving the mental health of children exposed to domestic violence. Furthermore, identifying whether these protective factors only buffer against poor mental health under certain conditions will help us determine whether such interventions should be tailored to children and young people based on their characteristics and trauma exposure.

Alongside this, we would like to identify whether these factors (if any), protecting children and adolescents from internalising symptoms, are specific to the contexts of domestic violence exposure and mental health or whether they may be protective against other behavioural problems and in the context of exposure to other adverse childhood experiences such as parental alcohol/substance abuse, parental mental health problems, direct child abuse and neglect. This will also inform the potential scope of future interventions.

Increased breast density is strongly associated with increased breast cancer risk, however, the underlying biology is unclear.
We aim to identify genetic variation associated with breast density to help explain this association.

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a unique resource with a wealth of rich longitudinal data. Furthermore, ALSPAC is one of the few longitudinal cohorts with repeated assessments of self report psychiatric traits, along with a host of early exposures and later outcomes. As such, ALSPAC is a vital tool for exploring the longitudinal nature of psychiatric traits, their antecedents and later consequences.

Examining the nature of psychiatric disorders such as depression is complex and often requires advanced statistical methods to untangle complex associations and underlying mechanisms. Currently, there are few open access datasets with enough detail available for researchers to learn these complex statistical methods. As such, many researchers are forced to use datasets that do not capture the complexity of traits such as depression, and this could hinder the ability to make further progress in uncovering diseases like depression.

Given the sensitivity of the ALSPAC study, it is not appropriate to release full versions of the data. However, it is possible to simulate parts of the ALSPAC data to give the same properties, without the risk of disclosure and identification of participants.

Simulating ALSPAC data that matches the original properties of the data would provide an excellent resource for teaching purposes as well as providing an introduction to researchers wanting to use the original ALSPAC study.

In our ageing population the burden of both heart failure (HF) and dementia is increasing. To date there is no proven preventative or curative treatment for cognitive decline and the associated social and economic cost is huge. Both conditions share common risk factors, yet there is growing evidence of a direct relationship between the function of the heart and the brain. But we still don't know if poor cognition is a consequence or a cause of poorer cardiac function. Several aspects of this association require thorough investigation. We propose that there is a bidirectional association between cognition and cardiovascular disease (CVD) and by applying sophisticated techniques to assess cardiac and brain structure and function, this investigation will significantly advance our understanding of the causal mechanisms underlying both cardiac and cognitive decline.

Breastfeeding is life-saving for some vulnerable populations (eg poor sanitation contexts) and individual babies (eg preterm), however breastfeeding according to WHO guidelines remains rare in the UK and other high-income countries. Other than the obvious lack of support for new mothers starting their breastfeeding journey, little is known about individual barriers to breastfeeding, some of which could be specific to the mother, and some could be specific to the baby.
This project aims to understand to what extent the mother and baby's genetic make up can influence the pair's chances of starting and sustaining breastfeeding.
This knowledge will help in several ways, and specifically:
1. it will allow researchers to conduct robust studies into the health effects of breastfeeding for mothers and babies,
2. it will shed light onto needs and approaches that could be used to help support breastfeeding.