Genetic links to drug and alcohol use among young people

Young people who are genetically predisposed to risk-taking, low extraversion and schizophrenia are more likely to use alcohol, cigarettes, cannabis, or other illicit drugs, according to a new UCL-led study.

The researchers say that the findings, published in Addiction Biology, are in line with the notion that people who are more vulnerable to psychopathology or certain personality traits are more inclined to try several types of drugs or use them to ‘self-medicate’.

They say their findings also align with theories that the brain’s reward system is implicated in the use of multiple substances.

While some people appear to be genetically predisposed to using multiple drug types, the researchers also found that some traits had different effects, depending on the substance. A genetic predisposition to high educational attainment predicted higher use of alcohol and illicit drugs, but lower use of cigarettes, while predisposition to high body mass index had the opposite correlations.

The researchers hope their findings could inform strategies for the prevention and treatment of substance use disorders.

Senior author Dr Jean-Baptiste Pingault (UCL Psychology & Language Sciences) said: “Our findings support the ongoing development of prevention programmes that are tailored based on the psychological and personality profiles of adolescents. Such programmes should have beneficial effects across substances.”

Co-lead author Dr Tabea Schoeler (UCL Psychology & Language Sciences) said: “Treatment and prevention programmes that target risk-taking behaviours among young people, while also focusing on adolescents with early signs of schizophrenia, could be beneficial in reducing the risk of developing substance use problems.”

Co-lead author Dr Eleonora Iob (UCL Institute of Epidemiology & Health Care) said: “Our evidence also suggests that some predispositions make young individuals more likely to use specific substances. For example, we found that adolescents predisposed to high body mass index were more likely to smoke cigarettes. As nicotine is known to suppress appetite, those individuals may smoke more in an attempt to control their appetite. This should be carefully considered when designing interventions for smoking cessation.”

The study involved 4,218 participants of the University of Bristol’s Children of the 90s cohort study, who were assessed at ages 17, 20, and 22.