Anyone at all involved with the broad cannabis community has heard the story that marijuana has been getting more and more potent as time goes on.
But this claim has also been widely contested, as some have pointed out flaws in the way marijuana potency has traditionally been tested and recorded.
A new study that has been accepted for publication by the scientific journal Biological Psychiatry, however, claims that the story checks out.
The study was spearheaded by researcher Mahmoud A. ElSohly, who runs the Marijuana Research Project at the University of Mississippi.
In it, ElSohly’s team studied nearly 39,000 samples of cannabis that had been confiscated by US law enforcement agents between January 1, 1995 and December 31, 2014.
After compiling and analyzing various data sets from these samples, the researchers attempted to identify any possible trends in the overall potency of marijuana.
Here’s what they found:
“Overall, the potency of illicit cannabis plant material has consistently risen over time since 1995 from approximately 4% in 1995 to approximately 12% in 2014,” researchers wrote.
“On the other hand, the CBD content has fallen on average from approximately 0.28% in 2001 to 0.15% in 2014, resulting in a change in the ratio of THC to CBD from 14 times in 1995 to approximately 80 times in 2014.”
Apparently, marijuana really is getting more potent over time—at least in the samples the group of researchers looked at.
But critics have pointed out some potential problems with the way trends in marijuana potency have been recorded.
For example, researchers have pointed out that the data on marijuana potency gathered back in the 1970s and ’80s came largely from weak crops that had been seized by DEA agents and cops.
As a result, the numbers for those decades—the numbers that are still being used in comparisons to today’s stats—could reflect lower potency levels than what most smokers may have actually experienced.
Similarly, studies that look only at samples confiscated by law enforcement fail to account for the wide variety of specially designed hybrid strains currently available, especially in legal dispensaries.
Today’s cannabis market actually includes a full range of potency levels, including everything from strains that are extremely high in CBD and low in THC to super-potent strains with high levels of THC.
And finally, some scientists have voiced concern over using gas chromatograph testing methods—which ElSohly’s research team said it used in their study—saying that this technique could unintentionally alter the THC molecules in the cannabis samples being analyzed.
(Photo Credit: Shutterstock)