Addiction medicine specialist Professor Nick Lintzeris shares expert insights on the role of medicinal cannabis as a treatment approach for cannabis use disorder.
Australia is at the forefront of research examining the role of medicinal cannabis as a treatment approach for people living with cannabis use disorder (CUD).
Professor Nick Lintzeris, from the University of Sydney, is one of Australia’s – and the world’s – leading addiction medicine specialists and clinical researchers.
During a webinar hosted by Penington Institute, Professor Lintzeris suggested medicinal cannabis could play several important roles in the management of CUD: managing withdrawal, facilitating reductions in use and eventual abstinence, and reducing harm among people who continue cannabis use.
“We haven’t had much success in finding efficacious medications, which prompted a lot of people to start thinking, ‘is there a role for medicinal cannabis in treating cannabis use disorder?’’’ Professor Lintzeris said.
What is cannabis use disorder?
Cannabis use disorder is a chronic bio-psycho-social condition involving regular cannabis use despite clinically significant impairment.
“A lot of symptoms revolve around continuing to use cannabis despite there being persistent harms (such as cravings, inability to quit, not coping with the resulting social problems, etc),’’ Professor Lintzeris said.
While CUD affects only a small minority of people who use cannabis, it is significantly more common among people who use the drug daily.
The National Drug Strategy Household Survey for 2022 showed about 12 per cent of the Australian population – or roughly 2.5 million people – have used cannabis in the past 12 months.
How could medicinal cannabis be used in treatment?
Professor Lintzeris outlined how medicinal cannabis could help those who struggled with withdrawal symptoms when they were attempting to stop consuming cannabis.
“There is the need for a stepped care approach – many cannabis users stop with minimal withdrawal discomfort,’’ he said. “For others it might involve ‘standard care’ support (getting organised, dealing with cravings, sleep, exercise) and short-term medication.”
But when standard care is not effective, “that’s when I would suggest thinking about the role of medicinal cannabis.”
“Generally, we would recommend a short-term treatment program, say 7-14 days, which is consistent with a period of maximal withdrawal severity…The idea is that we use tapering doses over that 7-14 day period.’’
Professor Lintzeris recommended using oral THC rather than vaporised THC: “This is partly to break the behavioural association of reaching for a joint or a bong, but also because oral medication is longer acting.’’
Evidence for the role of medicinal cannabis in treating cannabis use disorder
In relation to CUD treatment, Professor Lintzeris pointed to a study he published in the Journal of the American Medical Association in 2019.
It found that trial participants who used nabiximols (a specific cannabis extract) significantly reduced their illicit cannabis use, whereas those in the placebo arm continued to use cannabis 6-7 days a week over the 12-week period of the trial.
“And those benefits persisted when they checked in with patients three months after the completion of the study,’’ Professor Lintzeris said.
He also stressed that a combination of medication and counselling was proven to produce better outcomes.
Medicinal cannabis and harm reduction
In the area of harm reduction, Professor Lintzeris highlighted several benefits associated with medicinal cannabis.
These include using cannabis products that are safer than those sourced from the illicit market; encouraging safer routes of drug administration such as oral formats instead of smoking; facilitating goals to reduce use levels; avoiding legal problems; and addressing related health issues such as mental health and tobacco use.
Professor Lintzeris also said that early data about the use of cannabidiol (or CBD) was promising about the role it could play a role in treating cannabis use disorder.
He noted that CBD is not intoxicating, there is no dependence or withdrawal, and it does not produce positive results in roadside or urine tests. CBD may also counter some of the unwanted effects of THC, such as anxiety or psychoticism, although further research is needed in this area.
People may have access to CBD through the unregulated, illicit cannabis market, but evidence suggests CBD is either absent or found in minimal quantities in these products.
The future of medicinal cannabis regulation in Australia
Professor Lintzeris closed his presentation by placing medicinal cannabis for CUD within the broader context of Australia’s cannabis framework. He noted that the simple decriminalisation of cannabis would not address problems around quality control, crime and improved health support.
“There is a role for medicinal cannabis for people that actually want to change their relationship with their cannabis use and improve their health,” Professor Lintzeris said.
“There is also a role for prescription or regulated cannabis supply for people who basically just want to keep using cannabis.
“Because Australia has no regulated cannabis system in place, this is the closest parallel we have in Australia to a regulated cannabis supply. And people are legitimately asking the question: Is that the role of medicinal cannabis?
“And the debate there is a debate we need to have. One of, ‘what would a regulated cannabis market look like alongside a medicinal cannabis market?’”
Watch the full webinar, ‘Cannabis Use Disorder: Insights from Professor Nick Lintzeris’, on-demand.
