For the longest time, the results of a 2014 study published in the Journal of the American Medical Association showed a compelling correlation with opioid deaths in states with medical marijuana.

According to the study, medical marijuana states experienced approximately 20% less opioid-related deaths than states who banned cannabis use. This soon became a key talking point for marijuana advocates, including here at WeedAdvisor.

But now, Vox discusses a new study with a very different conclusion. Now, rather than a 20% decrease in opioid deaths, states with medical marijuana registered a 20% increase. The study did not deviate from its predecessor in terms of methodology, so it left many people scratching their heads.

Bleak as it seems, however, this does not mean that marijuana actually leads to opioid use. The issue is not that the correlation has changed, but rather that there was no correlation in the first place.


Widespread Hype


When the original study was published in 2014, it represented a glimmer of hope for states struggling with the opioid epidemic. It also did not hurt that this revelation significantly bolstered the argument for legal marijuana. Ultimately, this led to rapid action.

According to Vox:


“Previous studies, particularly a widely cited 2014 study, found a correlation at the state level between the legalization of medical cannabis and fewer overdose deaths. That line of research indicated that medical marijuana may lead to a reduction in overdoses, under the theory that people could use cannabis to treat pain rather than opioids. Some state lawmakers embraced the studies, citing them to legalize medical pot or allow medical marijuana to help treat opioid addiction.”


With promises like these and the situation growing increasingly desperate, it is no surprise that legislators and the public both pounced on this golden ticket.


A Broader Picture


One limitation was that the 2014 study only covered opioid deaths from 1999 to 2010. But the most recent one was able to gather data up until 2017, providing radically different results:


“The new study, published in PNAS, found that medical marijuana was correlated with fewer opioid overdose deaths from 1999 to 2010. But using newer data up to 2017, the study found that states with medical marijuana laws actually saw more opioid overdose deaths.”


At this point, anti-cannabis advocates might see this as their own gift. What better news than a study showing a positive correlation between opioid overdoses and cannabis?


But this is also simply not true.


No Correlation


These new revelations may be disappointing to legislators, the medical community and legalization proponents. However, this is simply another case of “correlation does not equal causation” rearing its head in otherwise sound research.

In the 2017 study, the authors essentially dismissed the idea of there being a link in the first place. According to Vox:


“The researchers argue that the correlation is spurious — suggesting that there’s no broad, generalizable connection between medical marijuana and opioid overdose deaths, and the previously found link was likely a coincidence.”


Chelsey Leigh Shover, the study’s lead author, says:


“We, the authors, think it’s a mistake to look at that and say, ‘Oh, cannabis was saving people 10 years ago and it’s killing people now. We think a more likely interpretation is that passing medical cannabis laws just is not affecting opioid deaths at the population level.”


In a way, it is good that researchers discovered this problem. Both the public and lawmakers put a lot of faith into medical marijuana’s ability to prevent or treat opioid addiction. Now that the link has been effectively busted, we can focus on other solutions.


WeedAdvisor’s Interest in Marijuana Research


Despite the news being less than stellar, studies like these are the reason WeedAdvisor supports ongoing cannabis research. We want experts to reveal new and exciting benefits, but it is equally important that misinformation about cannabis be exposed and corrected.

Thanks to the dedication of a few researchers, we now have a better understand on what marijuana does and does not bring to the table.

Although we are disappointed that a talking point we used is now effectively null and void, our focus on education compels us to provide a correct narrative.