On the forefront of cannabis research
Centre at McMaster and St. Joseph’s is uniquely positioned to be an ‘incubator’ to stimulate medical studies into the use of marijuana
INSIDE
A LAB at McMaster University, researchers are working to measure how effective cannabis might be to treat nerve pain, with a specific focus on the differences between what works for men and women.
The work, using rats with surgically imposed sciatic pain, is one of about a dozen projects funded in part through the Michael G. DeGroote Centre for Medicinal Cannabis Research.
The preliminary results from the trial show promise for pain relief.
Many of the more than 100 animals they have worked with show no sign of pain for many weeks after the initial two-week cannabis oil treatment, said Katja Linher, a research associate in the lab of Gurmit Singh, professor of pathology and molecular medicine at McMaster.
The most promising results have been when treating with higher dosages that include both the tetrahydrocannabinol (THC) and cannabidiol (CBD) — two of the cannabinoids that exist in cannabis.
THC is psychoactive, while CBD may reduce pain and inflammation.
In anticipation of pending recreational legalization in Canada next month, there is a flurry of cannabis research happening across Canada and North America, but the centre at McMaster University and St. Joseph’s Healthcare Hamilton is uniquely positioned to be an “incubator” to stimulate research into cannabis, says the centre’s co-director James MacKillop.
The centre is “not bricks and mortar,” but more of an “intellectual
nexus” that brings together McMaster researchers from across disciplines, he said.
This includes “seed funding” and also access to laboratories at the university and neuroimaging technology at St. Joe’s.
The medicinal cannabis centre has been around for a little over a year and is funded by a philanthropic donation.
The researchers also partner with outside companies, including some who have agreements with specific licensed producers, but the centre itself does not have an exclusive relationship with cannabis companies and retains the right to publish no matter the results.
MacKillop is a professor of psychiatry and neuroscience.
His co-director is Jason Busse, an associate professor of anesthesia.
Together they represent the two sides of research, the “yin and the yang” — addiction and mental health, and pain.
But while the focus is on medical cannabis, they cannot ignore recreational legalization, announced as the centre was establishing.
“We recognize that as a cannabis research centre it would be a little bit ostrich-head-in-the-sand to ignore the fact there is a huge change in the regulatory environment,” MacKillop said. He called legalization a natural experiment.
It’s also increasingly clear that the line between medical and recreational cannabis is blurred, Busse said.
For instance, in surveys for people who use cannabis for arthritis pain, most also say they use cannabis recreationally.
“It’s hard to find that pure (medical) group,” he said.
That’s not a problem for cannabis research, just a reality, they said.
The centre’s approach is to always be “evidence based” whether they’re looking at cannabis as medicine for pain, anxiety or sleep, or looking at dangers.
The nerve-pain study with rats is one of the furthest along of about a dozen studies funded by the centre.
Neither Linher or Singh initially set out to be cannabis researchers, but because their focus was on pain, they decided to look at whether cannabis was an effective treatment. “We just dove in,” Linher said. The rats — who are monitored by a veterinarian, are bred specifically for labresearch and only participate for up to 10 weeks — undergo a “cuffing” procedure that causes sciatic pain.
After the animals are studied for their reactions to pain and they are euthanized, researchers examine samples looking for biomarkers of pain, which could lead to future studies and eventually, to treatment.
A focus of the research is the differences between male and females, but more work is needed because the results from female rats is less consistent.
Immune systems and hormones are known to play a role in pain and a female’s cycle can make that harder to measure.
As part of the research Singh said
ON MENTAL HEALTH AND ADDICTION
Patterns of cannabis use: Groups will be followed over time to see what is the impact of cannabis legalization. Surveys will be done six, 12 and 18 months after legalization to measure changes in cannabis use, behaviour, impact on alcohol consumption, health etc. This is being led by centre co-director James MacKillop.
Price and behaviour: McMaster researcher Michael Amlung is studying the impact pricing will have on how much legal cannabis people are likely to buy. The work includes a published U.S. paper and a similar Canadian study under review. The Spectator has spoke with Amlung about his work, which found people prefer legal cannabis over the black market, particularly when it’s priced well.
Neuroimaging: Looking at whether people with cannabis use disorder (clinical name for addiction) have deficiencies in the reward processing part of their brain. Study, which is still in recruiting phase, includes already diagnosed patients getting brain scans while they react to different reward paradigms (such as winning rewards). Results are not expected before the new year.
Cannabis misuse systemic review: A study pulling together data from about 40 different studies that tracked young adults who have misused cannabis, looking at risky or harmful behaviour and what interventions have worked best for treatment. Final parts of data are being extracted, with manuscript possible later this year.
Anxiety pilot: Will be a randomized control pilot where patients are given CBD as an anxiety treatment. Researchers are still in very early phase.
ON PAIN
Systemic review of non-cancer pain: Led by centre co-director Jason Busse, study has reviewed about 30 trials where cannabis was used to treat non-cancer pain. Review has found a “statistically significant, but modest benefit in terms of pain relief.” What makes this review stand out is also how it analyzed pain — most studies just look at average effect, Busse said. But this review is looking at the “proportion,” meaning that some people can get much better responses than others. He found about 12 per cent of patients will get “important relief,” which could be useful information to doctors because they’d have to try about eight patients to find one where cannabis significantly works. “It’s probably not going to be a miracle, but for some patients it appears to be a reasonable alternative.”
DATACANN: Building a database of patients prescribed cannabis for non-cancer chronic pain. Patients will be followed over time to better understand clinical outcomes.
Knee-replacement surgery pilot:A
randomized pilot trial using 40 patients undergoing total knee replacement to see if CBD in isolation helps reduce inflammation and pain after surgery. The hope is to be able to begin recruitment later this year and have all patients recruited over a six-month period.
Orthopedic patient perspectives: A series of surveys with orthopedic patients to measure attitudes around pain medication and cannabis. It has revealed that many patients do not want to smoke cannabis, but prefer pills or oils. This work has triggered a secondary study in the works that will include interviews with chronic pain patients about the stigma of medicinal cannabis use and how that may impact their behaviour — would they hide cannabis use? or take it secretly?
Doctor data: Using non-identifying data gathered from doctors who been approving cannabis for patients for a decade to understand demographics of cannabis patients. Could include data from around 1,000 patients. he contacted Raphael Machoulam, known as the “father of cannabis,” in Jerusalem, who gave them a sample of cannabis that is 1,000 times more potent than cannabis here.
They will continue looking at the difference between male and female rats, tracing nerve pain, and looking for new cannabis compounds. The hope is to eventually move to human trials.
At the Michael G. DeGroote Pain Clinic at McMaster, which sees more than 20,000 patients a year, Busse said doctors are recommending cannabis to patients, including specific strains (THC to CBD ratio).
Much of this comes from the individual doctors’ observations.
But cannabis has been taboo for a long time, with many physicians and oversight bodies wary about endorsing cannabis as medicine. There has not been enough research.
“There is a lot of anecdote and hope for patients, but not a lot of strong studies,” Busse said, noting that many of the studies that have happened have been very small and did not follow patients for a long period of time.
There is also a big push to find alternatives to opioids, which are addictive and can be fatal when people overdose. You can overdose on cannabis, but you will not die.
“I think if we can give physicians more solid numbers, many may be more comfortable,” Busse said.
“Right now there is no training in medical school around the use of cannabis.”
Other research looks to better understand cannabis misuse, including the most severe cannabis use disorder — the clinical name for cannabis addiction — and other impacts on mental health.
Some of the research is systemic reviews of existing studies to look for bigger trends and others are smaller pilots that hopefully pave the way for full-sized trials.
“Trials are really expensive and very challenging to do,” MacKillop said.
“As a centre we can’t write blank cheques ... be we can provide incubator or seed funds ... pilots are feasibility studies that lay the foundation.”