Some 22 million people around the world reportedly live with cannabis use disorder (CUD), a condition typified by cravings and withdrawal symptoms when marijuana isn’t taken.
Yet, according to a new study from Lancet Psychiatry, a promising treatment for cannabis dependence could be one of the drug’s own compounds: CBD, the famously calming cannabinoid.
After running a randomized controlled clinical trial – the first of its kind for CBD and CUD – the researchers behind the new study found that participants who took CBD had more cannabis- abstinent days compared to those given a placebo.
Kicking the habit
At the start of the trial, 48 volunteers were recruited, all of whom were deemed to be living with CUD.
“This was done using a clinical interview and screening assessment using the DSM-5,” Dr Tom Freeman, an addiction researcher at the University of Bath and lead author of the study, told Analytical Cannabis.
“[DSM-5 is] a psychiatric classification system and there are 11 possible symptoms of cannabis use disorder and we had criteria that you had to have a moderate cannabis use disorder – at least four out of the eleven symptoms.”
The participants then agreed to stop consuming cannabis for the trial period and to instead take four capsules a day when prompted via text messages. For some participants, these four capsules amounted to 200 milligrams (mg) of CBD per day. Others could be consuming 400 mg or 800 mg per day, and some volunteers took placebo capsules that didn’t contain any CBD. But all participants were unaware of their particular dosage.
“Because it was the first trial of its kind, we didn’t know which does might be effective or safe,” Freeman said. “So we started with a range of possible doses: 200 mg, 400 mg, and 800 mg per day. And we used a matched placebo.”
Urine samples were regularly collected so the researchers could test for cannabis compounds and thus ensure participants were sticking to their abstinence.
After the first stage of the trial, the researchers judged the 200mg dose of CBD as ineffective and removed it from the experiment. Once the second stage of the trial was completed – which involved 34 more participants – Freeman and his colleagues concluded from the urine samples and interviews that the 400mg and 800mg doses were helping participants stave off cannabis, at least compared to the placebo group.
“We know that CBD has contrasting effects to THC on the endocannabinoid system,” Freeman told Analytical Cannabis. “We know that THC is a partial agonist at cannabinoid receptors. But CBD has minimal direct activity at cannabinoid receptors.”
“At the same time, it does have properties that could be helpful in treating cannabis use disorder, such as inhibiting the effects of other ligands acting on the CB1 receptor and increasing endocannabinoids. And this is a potential mechanism through which it could be acting to alleviate the cannabis use disorder and help people cut down their use.”
But, despite this promising finding, Freeman is keen to dissociate the CBD used in the trial from the CBD available on the high street.
“The doses tested were higher than those available in over-the-counter CBD products,” he said. “And it’s important to realize that the lowest dose was ineffective, and the highest dose was more effective. So, I wouldn’t recommend people self-medicate using over-the-counter CBD products.”
The wider research
More research will be needed to validate CBD’s use as a CUD treatment, say Freeman and his colleagues. But some existing studies already support the team’s conclusions.
Published last year in JAMA Internal Medicine, a study from the University of Sydney found that participants treated with both counseling and the CBD:THC-mouth spray Sativex experienced fewer cannabis withdrawal symptoms and saw improvements in their 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 professor of addiction at the University of Sydney, told Analytical Cannabis at the time.
“The counseling and regular reviews had some benefits – but that these are enhanced when combined with active medication” he added. “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.”