Cannabis-Based Medications Can Help Tackle Dependency, Study Finds

A new study has provided the first strong evidence that cannabis-based medications can significantly reduce the rate of relapse for people with a cannabis dependency. 

For the randomised controlled trial, published in JAMA Internal Medicine, researchers from the University of Sydney treated participants with the cannabis-based mouth spray Sativex, which comprised roughly equal proportions of cannabidiol (CBD) and tetrahydrocannabinol (THC). 

After 18 sprays a day for 12 weeks and rounds of cognitive behavioural therapy, the participants were reported to have fewer cannabis withdrawal symptoms and cravings, and improvements in physical and psychological well-being. 

“This is the first study with sufficient power to allow us to draw conclusions regarding the efficacy of cannabinoid medicines for outpatient treatment of cannabis dependence,” Nick Lintzeris, the study’s lead author and conjoint professor of addiction medicine at the University of Sydney, told Analytical Cannabis.

Cannabis use disorder is an addiction to marijuana thought to affect around 1.5 percent of Europeans and Americans. The disorder is typified by cravings and withdrawal symptoms when cannabis isn’t taken, and recent research has hinted that it may have a genetic cause. 

“This study enrolled heavy cannabis users who were seeking to stop their use of cannabis and had been unsuccessful on previous ‘quit’ attempts,” Lintzeris explained. 

“They had been heavy cannabis users – smoking on average 2-3 grams a day – for extended periods of time – on average 10-15 years. Many were experiencing a range of health, relationship, and social problems associated with their cannabis use. Most reported it had become a habit that they could not easily stop.”

Over the course of the trial, participants treated with the Sativex spray experienced about 40 percent fewer illicit-cannabis-use-days than patients randomly allocated a placebo medication. 

Sativex, also known as nabiximols, has been licensed in many countries, including Switzerland, Turkey, and the United Kingdom, but primarily for patients with multiple sclerosis-related muscle spasticity. The University of Sydney study marks one of the few cases it has shown efficacy outside of MS-related treatment. 

Taking a leaf from holistic treatments like nicotine replacement therapy, the trial also incorporated counselling sessions between participants and trained therapists to identify key health and social issues.  

“The counselling and regular reviews had some benefits – but that these are enhanced when combined with active medication” said Lintzeris. “This is a finding generally consistent with the evidence from other areas of health care – that combined medication and counselling is often more effective than either approach alone.”

“There were high levels of patient satisfaction with approximately four in five patients reporting they would recommend this treatment approach to a friend requiring treatment,” he added. 

But although highly praised by its participants, the study did have its limitations, as Lintzeris notes. 

“We attempted to ‘blind’ the participants as to which group they were in (nabiximols or placebo), and it turns out that whilst a large proportion of people were unable to guess which group they had been allocated to, blinding was probably not effective for everyone,” he said.  

“Further research is required to better understand the optimal duration of treatment, and indeed to examine different ratios of THC and CBD.”

Previous studies have shown that the famed cannabinoid CBD can also form the basis of effective addiction treatments for substances such as heroin, methamphetamine, and tobacco. 

In 2015, a Université de Montréal research team assessing CBD’s potential as an addiction treatment concluded that “emerging data remain very limited and are far from being conclusive; well-designed, randomized, controlled trials are necessary at this point to determine whether these properties translate into significant improvements on clinical outcomes in human populations.”

It now remains to be seen whether Professor Lintzeris’ randomized controlled trial will be enough to give CBD and Sativex such clinical validation.  

“Should this finding be replicated – it suggests we have a useful addition to treating individuals with cannabis dependence beyond ‘talking therapies,’” added Lintzeris.   

“Whilst many cannabis dependent users may not seek to stop their use, and some can stop without getting help, evidence suggests that many heavy cannabis users struggle in quitting cannabis.”

“Could this treatment one day be available in general practice and dispensed at a pharmacy? Absolutely. Cannabis dependence is a very common condition in countries such as Australia and the UK and treatment approaches need to be widely available. The medication was safe, well tolerated by patients, easy to use, and with few concerns.”