News Release

Research from King's College London reveals why some teenagers more prone to binge drinking

Peer-Reviewed Publication

King's College London

New research helps explain why some teenagers are more prone to drinking alcohol than others. The study, led by King's College London's Institute of Psychiatry (IoP) and published in Proceedings of National Academy of Sciences (PNAS) provides the most detailed understanding yet of the brain processes involved in teenage alcohol abuse.

Alcohol and other addictive drugs activate the dopamine system in the brain which is responsible for feelings of pleasure and reward. Recent studies from King's IoP found that the RASGRF2 gene is a risk gene for alcohol abuse, however, the exact mechanism involved in this process has, until now, remained unknown.

Professor Gunter Schumann, from King's IoP and lead author of the study says: "People seek out situations which fulfill their sense of reward and make them happy, so if your brain is wired to find alcohol rewarding, you will seek it out. We now understand the chain of action: how our genes shape this function in our brains and how that, in turn, leads to human behaviour. We found that the RASGRF-2 gene plays a crucial role in controlling how alcohol stimulates the brain to release dopamine, and hence trigger the feeling of reward. So, if people have a genetic variation of the RASGRF-2 gene, alcohol gives them a stronger sense of reward, making them more likely to be heavy drinkers."

Approximately 6 out of 10 young people aged 11-15 in England report drinking, a figure which has remained relatively stable over the past 20 years. However, binge drinking has become more common, with teenagers reportedly drinking an average of 6 units per week in 1994 and 13 units per week in 2007. In the UK, around 5,000 teenagers are admitted to hospital every year for alcohol-related reasons. Teenage alcohol abuse is also linked to poor brain development, health problems in later life, risk taking behaviour (drunk driving, unsafe sex) and antisocial behaviour.

The study initially looked at mouse models without the RASGRF2 gene to see how they reacted to alcohol. They found that the absence of the RASGRF-2 gene was linked to a significant reduction in alcohol-seeking activity. Upon intake of alcohol, the absence of the RASGRF-2 impaired the activity of dopamine-releasing neurons in a region of the brain called the ventral tegmental area (VTA) and prevented the brain from releasing dopamine, and hence any sense of reward.

The research team then analysed the brain scans of 663 14 year old boys – who at that age had not been exposed to significant amounts of alcohol. They found that individuals with genetic variations to the RASGRF2 gene had higher activation of the ventral striatum area of the brain (closely linked to the VTA and involved in dopamine release) when anticipating reward in a cognitive task. This suggests that individuals with a genetic variation on the RASGRF-2 gene release more dopamine when anticipating a reward, and hence derive more pleasure from the experience.

To confirm these findings, the researchers analysed drinking behaviour from the same group of boys at 16 years old, when many had already begun drinking frequently. They found that individuals with the variation on the RASGRF-2 gene drank more frequently at the age of 16 than those with no variation on the gene.

Professor Schumann concludes: "Identifying risk factors for early alcohol abuse is important in designing prevention and treatment interventions for alcohol addiction."

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The study is part of the IMAGEN Consortium, funded by the European Union with additional funding from the UK Medical Research Council (MRC). The consortium brings together scientists across Europe to carry out neuroimaging, genetic and behavioral analyses in 2,000 teenage volunteers in Ireland, England, France, and Germany. The IMAGEN project aims to investigate the roots of reinforcement behaviour and mental health in teenagers.

For a copy of the paper, or comment from the author, please contact Seil Collins, Press Officer, Institute of Psychiatry, King's College London.
Email: seil.collins@kcl.ac.uk
Tel: 0207 848 5377 Mob: 07718 697 176

Paper reference: Stacey, D. et al. 'RASGRF-2 regulates alcohol-induced reinforcement by influencing mesolimbic dopamine neurone activity and dopamine release' Proceedings of the National Academy of Sciences (PNAS) 2012

About King's College London:

King's College London is one of the top 30 universities in the world (2012/13 QS international world rankings), and was The Sunday Times 'University of the Year 2010/11', and the fourth oldest in England. A research-led university based in the heart of London, King's has more than 24,000 students (of whom more than 10,000 are graduate students) from nearly 140 countries, and more than 6,100 employees. King's is in the second phase of a £1 billion redevelopment programme which is transforming its estate.

King's has an outstanding reputation for providing world-class teaching and cutting-edge research. In the 2008 Research Assessment Exercise for British universities, 23 departments were ranked in the top quartile of British universities; over half of our academic staff work in departments that are in the top 10 per cent in the UK in their field and can thus be classed as world leading. The College is in the top seven UK universities for research earnings and has an overall annual income of nearly £525 million (year ending 31 July 2011).

King's has a particularly distinguished reputation in the humanities, law, the sciences (including a wide range of health areas such as psychiatry, medicine, nursing and dentistry) and social sciences including international affairs. It has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA and research that led to the development of radio, television, mobile phones and radar.

King's College London and Guy's and St Thomas', King's College Hospital and South London and Maudsley NHS Foundation Trusts are part of King's Health Partners. King's Health Partners Academic Health Sciences Centre (AHSC) is a pioneering global collaboration between one of the world's leading research-led universities and three of London's most successful NHS Foundation Trusts, including leading teaching hospitals and comprehensive mental health services. For more information, visit: www.kingshealthpartners.org.

The College is in the midst of a five-year, £500 million fundraising campaign – World questions|King's answers – created to address some of the most pressing challenges facing humanity as quickly as feasible. The campaign's five priority areas are neuroscience and mental health, leadership and society, cancer, global power and children's health. More information about the campaign is available at www.kcl.ac.uk/kingsanswers


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