Prescription CBD is safe for daily use in treating cannabis use disorder, according to a new trial published in The Lancet Psychiatry journal. The trial is the first of its kind to suggest that CBD – a major active compound found in the cannabis plant – can be used to treat cannabis addiction.

The double-blind, randomised, controlled trial was carried out over four weeks with 82 participants with a cannabis use disorder. All 82 people had been diagnosed with a cannabis use disorder of at least moderate severity, and had all expressed a desire to quit within the next month, and had tried to quit on at least one occasion before.

Cannabis use disorder is defined as the continued use of cannabis despite clinically significant impairment.

The participants were asked to take two capsules of CBD twice daily for four weeks. The placebo group were given capsules containing no CBD, while the others received a daily dose of either 200mg, 400mg or 800mg CBD.

Researchers found a daily dose of between 400mg and 800mg of CBD reduced participants’ cannabis intake. Abstinence from cannabis use increased by an average of 0.5 days per week in the group who received the 400mg daily dose of CBD and 0.3 days per week in the group who received 800mg CBD daily.

There were no serious adverse events during the study, suggesting that CBD is safe and well tolerated at the doses tested.

Dr Tom Freeman, the study’s lead author and Director of the Addiction and Mental Health Group at the University of Bath, UK, said: “Our study provides the first causal evidence to support cannabidiol, or CBD, as a treatment for cannabis use disorders. This is encouraging, as there are currently no drug treatments for cannabis addiction. CBD products are widely available in many countries but we would not advise people to self-medicate with these products. People with concerns about their cannabis use should always speak to a healthcare professional in the first instance.”

Professor Valerie Curran, senior author and Director of the Clinical Psychopharmacology Unit at University College London, UK, added: “Our findings indicate that CBD doses ranging from 400mg to 800mg daily have the potential to reduce cannabis use in clinical settings, but higher doses are unlikely to bring any additional benefit. Larger studies are needed to determine the magnitude of the benefits of daily CBD for reducing cannabis use.”