Kick back: it’s legal in Colorado (Image: Ana Nance/Redux/Eyevine)

IT IS considered a soft drug, but increasing numbers of people are seeking help for cannabis addiction – and there’s growing interest in finding ways to treat them.

Paradoxically, the most promising treatment may be an extract of cannabis. Last month, researchers at the British Neuroscience Association meeting in Edinburgh, UK, described how the compound, called cannabidiol, helped one person who was severely addicted. A clinical trial is underway.

Unlike most forms of drug addiction, there are no medical treatments to help people reduce their cannabis use. “Cannabis dependence is a huge unmet need with no pharmacological treatments,” says Tom Freeman of University College London, who is involved in the trial. “It’s vital we get one.”


A possible connection between smoking pot and schizophrenia is fairly well known, but the link is controversial and it affects only a small minority of users. Addiction seems to be a more common problem – yet is often overlooked.

There is no universal definition of addiction or dependence. Someone is usually deemed to be addicted to a drug if they want to stop but cannot, or if it has a negative impact on their life. They would probably be experiencing withdrawal symptoms that make it hard to give up. In the case of heavy cannabis use, these can include anxiety and insomnia.

It is unclear how many marijuana users get hooked. A commonly quoted figure is that about 9 per cent of regular users become dependent, which probably stems from a US study from the 1990s.

This would make cannabis relatively non-habit-forming compared with other drugs – the same figure for heroin is 23 per cent and for alcohol is 15 per cent. Yet the risks of cannabis addiction are compounded because people think it is non-addictive, says Luke Mitcheson, who treats drug users at South London and Maudsley NHS Foundation Trust. “The perception is that it’s fine, but we shouldn’t underestimate its habit-forming potential.”

What is less controversial is that the number of people looking for help with their cannabis use is on the up, especially among teenagers. In the past decade the number of under-18s seeking treatment for cannabis addiction has risen by 50 per cent. “People are coming for help and you can’t argue with that,” says Freeman.

The number of teenagers seeking treatment for addiction has risen 50 per cent in the past decade

This may be because the cannabis available is becoming more potent, with increasing levels of THC, the compound that gets you high. Prolonged exposure to THC leads to lower levels of the brain’s natural version of this substance, a chemical called anandamide.

Levels recover after stopping the drug, but in the meantime there are withdrawal symptoms. That’s why cannabidiol, another chemical in cannabis, might help as it boosts anandamide.

In 2012, doctors in São Paulo in Brazil suggested synthetic cannabidiol as a treatment for a 19-year-old woman who had intense withdrawal symptoms whenever she tried to quit cannabis. She had smoked it daily since she was 13. Her symptoms eased within a day or two of taking cannabidiol, and she managed to quit. This suggests a way to help people through withdrawal, José Crippa of the University of São Paulo told the conference.

Freeman’s team at UCL is doing a randomised trial comparing cannabidiol with a placebo in 48 people, expanding to 168 people if the first results are positive. “We shouldn’t overstate the results of a single case,” says Freeman. “But it’s going to be exciting to see what happens with this study.”

Another strategy being looked at is using THC itself as kind of substitution therapy, however Crippa points out this still leaves people addicted to THC.

Going legit Cannabis is being legalised or decriminalised in a growing number of countries. Yet it has more potential for addiction than people realise (see main story). That’s no argument for keeping it illegal, says Danny Kushlick of Transform, a UK think tank that campaigns to legalise drugs. “Drugs need to be legalised and regulated precisely because they carry risks. Why would you want to leave supply in the hands of organised criminals?” Kushlick also points out that keeping cannabis illegal makes it less likely that people will seek medical help if they have trouble quitting, for fear of a criminal record. And at the moment, drug dealers make more money by selling the most potent kinds of cannabis, which probably increases the risk of dependency.

This article appeared in print under the headline “A drug to treat cannabis addiction”