Excessive drinking and alcohol related harms in Adulthood: ALSPAC at 24

Reducing harm caused by alcohol is a key public health and policy priority. Liver disease deaths have increases over 4-fold in last 40 years. Over 1 in 3 young adults, both women and men, aged 20-24 drink excessively. These adverse patterns of drinking can originate in adolescence - with 50% of adolescents reporting binge drinking by aged 16. Several key alcohol related harms emerge in young adulthood, while others may persist into adulthood because of continued excessive drinking. The evidence on the relationship between patterns of excessive drinking and these key harms, especially how important early onset excessive drinking in adolescence is, needs to be strengthened. We aim to provide evidence on the proportion of young people who show signs of liver fibrosis/damage and the risk conferred by different patterns of alcohol use; the risk of poor cognitive and emotional processing associated with binge drinking; whether harmful alcohol use leads to depression in young adults; whether excessive alcohol use prevents people "maturing" out of antisocial behaviour; and amount of injury in young people associated with adverse patterns of alcohol use.
In addition, harmful alcohol use or alcohol dependence also emerges in young adulthood. Further evidence is required on the relative contribution of different pathways to alcohol dependence. We plan to focus on three key pathways: the role of early behavioural or conduct problems; the impact of depressed mood and anxiety in early life and adolescence; and the potential effect of physiological response to alcohol (assessed in terms of the average amount of alcohol it takes to elicit an effect).
Longitudinal data - which measures alcohol use over time, and social, environmental factors before and during alcohol use - are required to assess both of these issues - the influence of types of alcohol consumption on harm in young adulthood and pathways to problem alcohol use in young adulthood.
The ALSPAC birth cohort (Children of the 90s) is the most extensively followed birth cohort in the world with detailed biological and behavioural data from before birth to late adolescence and early adulthood. We propose to take the unique opportunity provided by ALSPAC to measure alcohol related harms and outcomes in 5000 young people aged 24/25. Testing the robustness and strength of the association between alcohol and harm or the importance of different pathways to alcohol dependence will be important. Two key problems are confounding (where an association maybe explained by another factor) and missing data (which is higher in people from lower socio-economic groups with the greater early behavioural problems). We will utilize a range of sophisticated statistical techniques that seek to address these problems, including the use where possible of genetic markers of alcohol consumption (which are unrelated to other factors) and can strengthen evidence on causation.
We are a multi-disciplinary team including leading experts in methodology, alcohol and related harms. The evidence we gather and data we collect will be beneficial to other academics working in the field, and critically to public and patient groups, clinicians and policy-makers with an interest in preventing alcohol related harm.

We will measure key alcohol related harms on 5000 ALSPAC participants aged 24/25 and test the association between patterns of alcohol use and risk/level of harm in young adults. These include:- liver fibrosis measured using biomarkers and fibroscan/ultrasound; three broad domains of neurocognitive function - executive function, emotion processing, and impulsivity - assessed using three specific tasks (n-back working memory task, the emotion recognition task, and the stop-signal task); depression and depressive symptoms measured by clinical interview (Clinical Interview Schedule-Revised CIS-R and Moods & Feeling Questionnaire MFQ); antisocial behaviour and offending measured by Edinburgh Youth Transitions Study Questionnaire and record linkage with Police National Computer; and Injury measured by record linkage and self-report questionnaire. Excessive and harmful alcohol use also will be measured at age 24/25 as an outcome - and three key pathways to these outcomes assessed based on the rich phenotypic data available within ALSPAC (externalising, internalising and low response to alcohol).

Latent class and latent growth modelling will be used to develop a range of alcohol phenotypes required for the different hypotheses raised. Statistical analysis will be based on Directed Acyclic Graphs (DAGs) to specify clearly the hypothesised causal pathways and effect of confounders. Missing data will be modelled, and where possible Mendelian Randomisation using genetic markers of alcohol consumption will provide a further test of the hypotheses.

The research outlined will provide robust evidence on the relationship between excessive drinking in adolescence and adult consumption, and the key consequences in early adulthood. The research outputs will inform the development and evaluation of interventions to prevent substance misuse. As such, the direct beneficiaries of this research will include researchers working on the development and evaluation of interventions to prevent substance misuse in adolescents as well as public health policy makers. Other beneficiaries include young people, their parents, teachers and youth group leaders as well as policy makers and the wider society.

Multidisciplinary research teams working to develop and evaluate interventions for adolescence substance misuse will benefit directly from access to the basic research that will inform and guide their work. Results will be shared with these groups through the classical pathways of scientific publications in peer reviewed journals, communications at national and international meetings, press releases and more targeted presentations.
Voluntary sector organisations provide a diversity of materials, advice and training to a range of engaged parties, including young people, parents of young people and health practitioners. The findings of this research will have the potential to directly inform these organisations, and enable them to further develop and target their efforts.

We anticipate the interest of policy makers, including central government and public health commissioners, who will use the outputs of the research to inform their current practice. Looking further into the future, improved and better targeted interventions can be anticipated, which these groups will be able to act upon.

Young people, parents and youth group workers will experience immediate impact from the research, as the direct findings of the research are reported through the media and other channels. Media coverage of research can be powerful in raising the awareness of issues, influences and consequences, and for stimulating debate and discussion. However, there is limited scope to change behaviours through communication alone, and for that reason it is through informing the development and evaluation of interventions that the impact of this research will be most strongly felt.
We are dedicated to disseminate information regarding our research to both direct beneficiaries and those able to influence policy within the UK. Utilising the network of contact between the investigators and many of the beneficiaries mentioned here, we will ensure the engagement of these stakeholders throughout the project and beyond it. The benefits of the research are likely to be realised very soon after completion of the project, due to our approach to stakeholder engagement, and will ensure the rapid mobilisation of research outcomes into further research and practice