The findings imply that the genetic influences associated with people taking up smoking also influence people being e-cigarette users; these were also found to be associated with risk-taking behaviours more generally, such as externalising disorders in childhood.

Previously, e-cigarette-use has been linked to an increased risk of smoking. However, if individuals are genetically more likely to both smoke and use e-cigarettes, policies which aim to prevent e-cigarette use by removing them from the market may actually encourage smoking where only cigarettes are available.

Dr Jasmine Khouja, lecturer at Bristol’s School of Psychological Science and a member of the University’s Tobacco and Alcohol Research Group, is lead author of the study which has been published in the health journal PLOS Medicine.

Paper: ‘Association of genetic liability to smoking initiation with e-cigarette use in young adults: A cohort study’ by Jasmine Khouja et al in PLOS Medicine.