Professor Alex Stevens:

Portugal has seen variations in rates of drug use over the past 20 years. People who advocate for decriminalisation have leapt on the times when its rates decreased and people who are against decriminalisation have leapt on the times when they have increased to try to prove their respective points. One of the most interesting studies compared the trends in young people’s drug use in Poland and Portugal. Poland is an interesting case because it almost did the opposite of Portugal at in or around the same times, but their trends in young people’s drug use are similar, suggesting that the decriminalisation or criminalisation of drugs has little effect on young people’s drug use. Indeed, this was the subject of a study I published in 2019, which looked at evidence from over 115,000 young people in 38 countries and compared those countries that did or did not have more liberal approaches to the policing of cannabis. It found no difference between those countries on that basis.

It is fair to be concerned about young people’s drug use. It tends to fluctuate more than adults’ drug use. We do not know much about its drivers, but we can be fairly confident that decriminalisation is not a driver of increased drug use among young people. We know there are things that can be done to reduce risk-taking behaviour by young people, and we should put it in that context. It is not just about drug use; it is about violence and early and unwanted sex. When we talk to teenagers, which I have done in research projects, about the things they are concerned about, they all go together in a package of the risks that young people face. There are things we can do about that to support young people, for example, giving them accurate information instead of scare stories about the risks. Measures like whole-school approaches and life skills training help young people to deal with the range of challenges they face in growing up in modern society.

It is not a hopeless story. There are things we can do if we want to invest in young people's lives, in both formal and informal education. Unfortunately, in my country, the UK, we have massively cut all these services. As would be expected and as we have seen, there have been increases in drug use and violence among young people in recent years. There are things we can do to prevent that.