The use of cannabis-based medications may help people with marijuana-dependency issues to significantly reduce their intake of the drug, according to a new study which is the first to make such a claim.

The University of Sydney researchers, who published their findings in the journal JAMA Internal Medicine, conducted a randomized controlled trial to assess the effects of a cannabis-based mouth spray Sativex, containing approximately equal proportions of cannabidiol (CBD) and tetrahydrocannabinol (THC), on those with a marijuana addiction.

Patients used the spray 18 times a day for 12 weeks whilst also receiving cognitive behavioral therapy. The participants following this regime reported an improvement in their physical and mental health, and less severe cannabis withdrawal symptoms and cravings.

“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,” said Nick Lintzeris, the study’s lead author and conjoint professor of addiction medicine at the University of Sydney.

Marijuana addiction is believed to affect around 1.5 percent of Europeans and Americans who exhibit withdrawal symptoms when they do not consume cannabis. Recent research has suggested that the condition may have a genetic basis.

“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.”

To compare the impact of the Sativex spray, some participants were randomly allocated a placebo instead, though all took part in the counseling sessions.

Patients treated with the Sativex spray reported 40 percent fewer illicit-marijuana-use days than those taking the placebo.

“The counseling 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 counseling is often more effective than either approach alone.”

Sativex is licensed in many countries but is typically used for patients with multiple sclerosis-related spasticity. The findings of the teams from the University of Sydney are among the first to suggest a use beyond MS-related treatment.

“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.

Though the results are positive, Lintzeris cautions against some of the limitations of the research.

“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.”

Recent research has indicated that CBD could form the basis for treating addiction to a range of substances, such as opioids, tobacco, and methamphetamine. Could cannabis be added to this growing list?

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

“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.”

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