New research was published this week highlighting the associations between teenage cannabis use and a range of mental health problems. The results suggested that use of the drug was associated with an increased risk of depression and a significantly higher risk of suicide attempts.

As usual in a study based on survey data, the authors noted that a clear line of causation from cannabis use to the reported effects cannot be drawn. There are always other potential mechanisms in action. Young people who use cannabis regularly may already be experiencing mental health issues that make drug use more likely; or be facing adverse life experiences that influence both their mental health and drug consumption.

Nevertheless, we cannot ignore evidence of a relationship between cannabis use among young people and mental health harms, especially as the strains of cannabis on the market become more potent. The question is how we can best address this challenge in ways that reduce harm.

The temptation is to call for more stringent enforcement of the law. The idea that we can deter use and restrict supply with tough policing has instinctive appeal. However, in reality, this approach has exacerbated and added to the harms we see. Prohibition has instead contributed to the market dominance of riskier high-THC, low-CBD products, and the continued linking of cannabis use to a wider illegal drug market that draws young people into criminalised environments. These both increase the risk of arrest, and of exposure to other drugs, as well as exploitation, including the more violent world of “county lines”.

Legal regulation may appear to be a soft response to the challenges we face, but it is not. Right now, people buying cannabis have no idea of the potency or even the contents, they do not receive health warnings or advice, and there are no age-access controls in place. Furthermore, profits from the trade go into organised crime, while billions more are spent on policing. Under legal regulation, cannabis would only be sold to adults, the market could be taxed, policing costs would fall and there would be more money to spend on proven prevention, treatment and harm reduction interventions. This is a public health issue and it requires a public health response. It only becomes a criminal justice problem when we treat it as one.

We need to take seriously the truth: cannabis use is already incredibly widespread but is dominated by the most potent products, sold in the riskiest environments. This is why Transform supports moves to legally regulate cannabis production and supply. We want to see the trade taken out of the hands of organised crime and regulated by the appropriate authorities.

We should not be naive about the possible risks. There are legitimate concerns about how this might affect the numbers using cannabis, but there is no strong evidence that use necessarily increases under legal regulation, particularly if it is done responsibly – with lessons learned from alcohol and tobacco policy, and appropriate controls on advertising and marketing. Policymakers have a responsibility to ensure regulation is done properly – although we now have an increasing range of real-world evidence from which to learn as more and more US states, Canada and Mexico take the route of legalisation. Legal regulation should not be understood as a money-making opportunity or commercial free-for-all, but as the pragmatic way to reduce criminality and protect health, particularly of young people. This has been the approach taken in Canada, and it is time our government looked at it seriously.

For this reason it is especially disappointing that the Independent Review of Drugs and Crime, announced by the Home Office this week, has explicitly put consideration of legal reform out of scope. However, the appointed chair, Dame Carol Black, has said she will look at the experiences in Portugal, Canada and other countries that have embarked on reform. The government may hope that ever more stringent policing succeeds where it has previously failed, but it cannot simply pretend there is no alternative on offer.

We need to take the risks of drug use, including cannabis, seriously and in doing so be prepared to think seriously about the alternatives. No one wants young people to experience avoidable mental health problems. Legally regulating supply provides us with the tools to protect young people, reduce criminality and make all cannabis use safer.

• James Nicholls is the chief executive officer of Transform Drug Policy Foundation







