There is no evidence that tough policies deter young people from using cannabis, a study has found. Analysing data about cannabis use among more than 100,000 teenagers in 38 countries, including the UK, USA, Russia, France, Germany and Canada, the University of Kent study found no association between more liberal policies on cannabis use and higher rates of teenage cannabis use. “My new study joins several others which show no evidence of a link between tougher penalties and lower cannabis use,” said Prof Alex Stevens, from the University of Kent’s school for social policy, sociology and social research.