Long-term cannabis study finds no significant relief for chronic pain

But there were some serious oversights.

Marijuana enthusiasts are in for a reckoning. While legalization is creating a billion-dollar industry and new champions are emerging from every angle, it’s also opening doors for new scientific research. Though marijuana is being shown to be helpful in a variety of ways, such as reducing opioid addiction rates in American states with legalized weed, not every anecdotal success story is holding up to closer scrutiny. 

New research from UNSW Sydney tracked 1,514 people suffering from chronic non-cancer pain for a median time span of a decade. At the end of this four-year study, one of the longest of its kind, the marijuana group reported experiencing more pain, did not cope with their pain as well, and said that pain interfered with their lives more than non-cannabis opioid users. 

A number of factors are at play. Firstly, a high percentage of participants suffered from mental health problems as well as chronic non-cancer pain. This should not be surprising, given that pain is often a neurological phenomenon regardless of how it manifests. The link between psychic and physical pain is often strong; they influence one another, just as anxiety and depression are sometimes shades of the same problem, one leading to the other.

While the median length of chronic pain was ten years, participants were recruited with as little as three months of experiencing chronic pain. They had to have been using opioids for at least six weeks. What might be the most uncertain aspect of this study is that cannabis users were not required to stop taking opioids. How marijuana interacts with opioids could play an important role in pain tolerance and perception. 

Interestingly, the researchers note that cannabis use did not lead to a drop in opioid usage, which is different from what has been happening in America: 

We found no evidence of a temporal relationship between cannabis use and pain severity or pain interference, and no evidence that cannabis use reduced prescribed opioid use or increased opioid discontinuation.

The authors then list reasons for discontinuation of cannabis, including lack of efficacy, access difficulties, and legal concerns. The latter two are not of concern to American citizens that live in states that have legalized marijuana medically or recreationally. The tension of acquiring marijuana or in fearing jail time in Australia could have influenced perceived efficacy. Due to this lack of control we should treat the results somewhat skeptically. 

Kyle Johnson, co-chair of the Cannabis Discussion Club, holds up a medicinal marijuana product at Trilogy at the Vineyards in Brentwood, some 55 miles east of San Francisco, California, on June, 21, 2018. - Seniors in the United States are increasingly turning to cannabis to treat their aches and pains as the craze for the drug spreads across the country and more states legalize it. (Photo: Josh Edelson/AFP/Getty Images)

Other studies have also not shown definitive proof of cannabis's efficacy in treating pain, however. A 2017 meta-analysis “found modest evidence supporting the use of cannabinoid pharmacotherapy for pain.” That is, of course, better than the results in Australia (based on a number of studies, not only one), but it’s also no shining endorsement. 

Then there’s the factor of the type of pain. As the pro-marijuana site, Leafly, states,

Chronic pain can be nociceptive or neuropathic. Nociceptive pain is caused by tissue damage or inflammation. Neuropathic pain is caused by nervous system damage or malfunction.

Leafly lists a number of studies backing up positive claims of treating pain at credible institutions, including Harvard. These are important, for if treatments for chronic pain include either opioids or cannabis, we need only look at the rising number of deaths and skyrocketing addiction rates as reason enough for seeking alternative therapies from our current established model of pill prescription. 

Still, that therapy replacing opioids must be equally effective. Whatever its causes, pain ruins lives. Not every opioid user is an addict; plenty of cannabis users experience pain relief. We must keep investigating. A controlled study, such as marijuana or opioids instead of marijuana and opioids if you want, is warranted. Deciphering types of pain is also necessary. Then we’ll get a better handle on what can actually work. 


Stay in touch with Derek on Facebook and Twitter.

3D printing might save your life one day. It's transforming medicine and health care.

What can 3D printing do for medicine? The "sky is the limit," says Northwell Health researcher Dr. Todd Goldstein.

Northwell Health
Sponsored by Northwell Health
  • Medical professionals are currently using 3D printers to create prosthetics and patient-specific organ models that doctors can use to prepare for surgery.
  • Eventually, scientists hope to print patient-specific organs that can be transplanted safely into the human body.
  • Northwell Health, New York State's largest health care provider, is pioneering 3D printing in medicine in three key ways.
Keep reading Show less

Adam Gopnik on the rhinoceros of liberalism vs. the unicorns of everything else

Torn between absolutism on the left and the right, classical liberalism—with its core values of compassion and incremental progress whereby the once-radical becomes the mainstream—is in need of a good defense. And Adam Gopnik is its lawyer.

Think Again Podcasts
  • Liberalism as "radical pragmatism"
  • Intersectionality and civic discourse
  • How "a thousand small sanities" tackled drunk driving, normalized gay marriage, and could control gun violence
Keep reading Show less

You weren't born ‘to be useful’, Irish president tells young philosophers

Irish president believes students need philosophy.

Personal Growth
  • President of Ireland Michael D. Higgins calls for students to be thought of as more than tools made to be useful.
  • Higgins believes that philosophy and history should be a basic requirement forming a core education.
  • The Irish Young Philosopher Awards is one such event that is celebrating this discipline among the youth.
Keep reading Show less

Fascism and conspiracy theories: The symptoms of broken communication

The lost practice of face-to-face communication has made the world a more extreme place.

  • The world was saner when we spoke face-to-face, argues John Cameron Mitchell. Not looking someone in the eye when you talk to them raises the potential for miscommunication and conflict.
  • Social media has been an incredible force for activism and human rights, but it's also negatively affected our relationship with the media. We are now bombarded 24/7 with news that either drives us to anger or apathy.
  • Sitting behind a screen makes polarization worse, and polarization is fertile ground for conspiracy theories and fascism, which Cameron describes as irrationally blaming someone else for your problems.
Keep reading Show less