This was published 5 months ago
Wonder drug or placebo: The confounding case of medicinal cannabis
Veteran Derek Pyrah used to feel like a zombie. He served in the Iraq War in 2003 and when he came back, he found himself jumping at shadows.
“A jet aircraft would fly overhead and I would think it was an incoming missile attack,” Pyrah says. He would obsessively check the family car for bombs, was irritable and forgetful and had flashbacks to things that happened in Iraq he still doesn’t talk about.
Derek Pyrah is lobbying the Department of Veterans’ Affairs to subsidise medical cannabis for his PTSD. Credit: Kate Geraghty
Pyrah was diagnosed with post-traumatic stress disorder (PTSD). Within a year, he says, he was on a cocktail of drugs including antipsychotics, antidepressants, anticonvulsants, mood stabilisers, valium, medication to put him to sleep, and medication to get an erection. His weight ballooned, he drank heavily, and his marriage fell apart.
“I was numb, emotionless, and felt like a semi-catatonic zombie with suicidal ideations,” Pyrah wrote in a submission to the Royal Commission into Defence and Veteran Suicide.
And then he watched a documentary about Iraq War veterans from the US who found cannabis relieved their symptoms. Pyrah scored some illicit pot and found his crippling anxiety dissolved and he could function.
Pyrah began self-medicating with cannabis. His other medication dosages were reduced and he stopped having panic attacks in public. He started volunteering at the canteen at his kids’ high school. But in 2020 he was arrested with half a kilogram of cannabis. The magistrate released him without conviction on the proviso he maintained treatment for his mental health. Pyrah found a doctor who could prescribe him medicinal cannabis.
Medical marijuana buds sold via prescription.Credit: iStock
“PTSD has a lot of symptoms. For me, there’s anxiety, there’s depression, there’s insomnia, mood fluctuations, there’s disassociation. Medicinal cannabis effectively targeted each one of those symptoms without any adverse side effects, without me feeling yucky.”
But Pyrah says medicinal cannabis is a rich person’s medication. He has applied multiple times to the Department of Veterans’ Affairs for funding for medicinal cannabis to treat his PTSD.
The department pays for medicinal cannabis for veterans with some conditions, including chronic pain and multiple sclerosis, on a case by case basis.
But Pyrah’s application was declined.
“There is currently insufficient evidence to support medicinal cannabis as an effective treatment for mental health conditions, including PTSD,” a department spokesperson says. “The Department of Veterans’ Affairs continues to actively monitor research in this space.”
The department’s position is supported by Associate Professor Gillinder Bedi, the head of substance use research at the Centre for Youth Mental Health at the University of Melbourne and a clinical psychologist.
“What we have at the moment is evidence from patients saying that it helps them and some naturalistic studies of people using cannabis for PTSD where there is some evidence that it may have an effect,” Bedi says. “But the evidence at the moment has a high risk of bias, we do not have high-quality evidence that it actually helps.”
Bedi says without large randomised controlled trials – where neither the participant nor the scientist know who is taking the medication and who is taking the placebo – it is impossible to conclude that medicinal cannabis is a safe or effective way to treat PTSD.
She is also concerned about the potential for developing cannabis use disorder, particularly if people smoke or vape cannabis with high levels of THC, the psychoactive ingredient that makes people feel high.
“This is essentially cannabis addiction and may affect between 10 and 30 per cent of people who use cannabis. The rates actually are quite similar in medicinal and recreational cannabis users.”
Derek Pyrah was a panellist at the launch of the inaugural Australian and New Zealand College of Cannabinoid Practitioners conference in Sydney.Credit: Kate Geraghty
Pyrah has formed the No More Zombie Veterans lobby group, which is campaigning for the Department of Veterans’ Affairs to subsidise medicinal cannabis for veterans with PTSD.
He is also a panellist at the launch of this weekend’s inaugural Australian and New Zealand College of Cannabinoid Practitioners conference in Sydney.
The conference is aimed at doctors, nurses and pharmacists and will explore the use of medicinal cannabis in the treatment of conditions including chronic pain, multiple sclerosis, PTSD, epilepsy, and insomnia.
The college’s president, Dr Orit Holtzman, is an authorised prescriber of medicinal cannabis and has treated more than 1000 patients with the drug.
“Our mission is to guide the practice of cannabinoid medicine to better the lives of patients, ensuring they receive the most informed and compassionate care possible,” Holtzman says.
The conference comes at a time when the efficacy and safety of medicinal cannabis is being debated across the world.
While many patients swear by the drug’s ability to ease chronic pain and relieve symptoms of PTSD, many experts say this is not supported by research to date and may just be the placebo effect.
Monash University’s Rachelle Buchbinder. Credit: Mario Borg
Professor Rachelle Buchbinder was part of a review, published in the British Medical Journal in 2021, of 32 trials of medical cannabis for chronic pain.
“There was almost no difference between if you took the cannabis or you took a placebo,” says Buchbinder, a rheumatologist and professor at the School of Public Health and Preventive Medicine at Monash University.
However, she said the medicinal cannabis had increased risk of side effects, including dizziness, cognitive impairment, vomiting, drowsiness and nausea.
“So we concluded that it results in minimal if any benefit in pain over placebo in almost all people and probably causes more harm than good.”
Buchbinder says at least two other reviews of the data had come up with similar conclusions.
Meanwhile, Australians’ use of the drug is booming, with an estimated 300,000 to 500,000 patients treated since medicinal cannabis was legalised in 2016.
Because there are almost no approved cannabis medicines, doctors can apply to the Therapeutic Goods Administration to prescribe it for compassionate use, such as for a terminally ill patient.
“Unfortunately, it’s become accepted practice by some people despite the best available evidence,” Buchbinder says.
In 2021, the International Association for the Study of Pain issued a statement saying it did not endorse the general use of cannabinoids to treat pain due to a lack of evidence from high-quality research.
However, the association stressed it did not wish to dismiss the lived experiences of people with pain who had found benefit from their use.
“This is not a door closing on the topic,” Andrew Rice, Professor of Pain Research at Imperial College London and the chair of the association’s taskforce on cannabis stressed in the statement, “but rather a call for more rigorous and robust research to better understand any potential benefits and harms.”
Gold Coasts Suns coach Damien Hardwick got pain relief from medicinal cannabis.Credit: Getty
For some people – such as Gold Coast Suns coach Damien Hardwick – medicinal cannabis has been life-changing.
Hardwick is no stranger to pain. In a playing career spanning a decade and two AFL football clubs, the steely defender was known for his toughness and aggressive playing style.
But after a biking accident more than a decade ago, Hardwick found himself struggling to cope with the chronic pain from his back injury.
“I was taking a variety of pills and I started to develop an ulcer from them,” Hardwick says.
“Someone said you should try medicinal cannabis and I, probably like most people, automatically thought of Bob Marley marching down the street smoking on a bong.”
But within three weeks of trying cannabidiol oil, known as CBD oil, Hardwick noticed a change in how he felt and slept.
“Instead of the pain being a six or seven out of 10, the level is probably a one or two, which makes it a lot more bearable,” he says.
“There was a stage where I had to be rocked out of bed. I haven’t had an episode like that for 2½ years now, which has been unbelievable. It allows me to exercise regularly every day without the fear of inflaming that injury, which I know is still there but is very much more manageable now.”
Hardwick has become such a zealot that he joined the sports advisory board at Levin Health, a medicinal cannabis company, alongside former rugby league player Andrew Johns, basketballer Lauren Jackson, North Melbourne Football Club coach Alastair Clarkson, former jockey Damien Oliver and former basketballer Andrew Bogut. Hardwick has also invested in the company.
Hardwick, who takes a milligram of CBD oil a day, says he now sleeps better, which he reckons improves the life of those who work for him because he is not in a foul mood.
“I’ll be less volatile in the coach’s box, too. It’s just made an enormous difference to me.”
How can we explain the disconnect between some medicinal cannabis patients’ glowing testimonies and the lack of scientific evidence showing the drug is effective?
For starters, the placebo response is often high in pain studies – a person’s physical or mental health appears to improve after taking a “dummy” treatment.
‘You break your arm and you go to ED. What you want them to do is give you some fentanyl not mess around with gummy bears.’
Professor Nicholas Lintzeris
But Nicholas Lintzeris, a clinical professor and addiction medicine specialist from the University of Sydney, also wonders whether the studies are asking the wrong questions.
“Most of the questions in pain studies are focused around how severe is the pain,” says Lintzeris, who is a speaker at the Australian and New Zealand College of Cannabinoid Practitioners conference in Sydney.
Lintzeris says medicinal cannabis will never replace opiates for acute pain. “Trust me, you break your arm and you go to ED. What you want them to do is give you some fentanyl not mess around with gummy bears.”
But chronic pain, he says, is complicated and exists on many levels.
Lintzeris says if pain studies posited different questions, such as, “Can you cope better with the pain after medicinal cannabis?” or “Is life better now?“, they might elicit a different response.
“When you actually go and talk to patients, overwhelmingly people will say ‘yeah, it’s working really well’.”
Lintzeris also says some – but not all – patients reduce their opioid use after starting medicinal cannabis.
While medicinal cannabis does not target the nerves where the pain is, Lintzeris says it might help with sleep, or dysphoria (an unpleasant mood state), or depression, or anxiety, which all affect how people process pain.
Some doctors prescribe it for chronic pain, Lintzeris says, alongside treatments including cognitive behavioural therapy, exercise, diet and physical therapies.
“It’s part of the toolkit,” he says. “It’s not going to work for everyone.”