Cannabis has been anathema for so long that pro-cannabis advocates feel the need to push the plant at every opportunity. This sometimes leads to individuals seizing on marginal studies as evidence of cannabis being the greatest things since sliced bread. We need to be incredibly careful, particularly since many of those studies are based in epidemiology.
Epidemiology is the practice of attempting to discover the root causes of a particular problem by establishing links. Unfortunately, epidemiology cannot go any further than that. It can only establish links between diseases and other things, but links do not establish cause and effect.
Just because a link is established between two things doesn’t mean that one thing causes the other. The danger of epidemiology is making unwarranted assumptions and then passing them off as science. Unfortunately, this is where we often find ourselves in the current cannabis environment.
Coming Out of the Woodwork
Choose your favorite cannabis news website and go look at the headlines. These days, it seems like stories discussing recent studies are coming out of the woodwork. Take the Marijuana Moment website. A recent perusal of their headlines reveals recent studies covering everything from impaired driving in cannabis friendly states to a reduction in foster care placements as a result of marijuana legalization.
Each of the reported studies shows some kind of link between legalized marijuana and a perceived social benefit. In every case, epidemiology has uncovered a correlation based on data. But it has not explained how. And without the how, there is no proof that one has caused the other.
It is possible that marijuana legalization has improved education and subsequently led to fewer DUI problems in cannabis-friendly states. But the study suggesting as much doesn’t prove it. All it does is present self-reported data indicating that people claim to drive while impaired less frequently in states where cannabis is legal.
A Questionable History
The unfortunate truth is that epidemiology has a questionable history. It is easy to find links between disease and other things if you look hard enough. But how often does science change its mind based on conflicting epidemiological studies? Too often.
Back in the 1970s, studies seemed to indicate that eggs and black coffee were bad for your health. If you wanted to live longer, you had to revamp the breakfast menu to include brand muffins and fruit juice. Only a few years went by before a conflicting study determined that eggs were fine, and coffee is actually good for you.
In the opinion of some, epidemiology is lazy science. This post does not take a position one way or the other. But it is clear that epidemiology is lacking in its ability to prove cause and effect. Establishing links proves very little. And the less data a study offers, the harder it is to accept a study as hard science.
Take a Cautious Approach
In light of what we know about epidemiology, it would be wise to take a cautious approach to the growing stream of new cannabis studies. In states like Utah, where Brigham City‘s Beehive Farmacy says lawmakers are very conservative, prematurely jumping on the latest studies as proof that cannabis is a good thing could ultimately alienate policymakers.
In more liberal states, where lawmakers seem eager to approve cannabis at every turn, putting too much stock in epidemiology can give consumers an incorrect perception of cannabis. The point is that epidemiology is only of limited value. So many epidemiological studies promoting cannabis consumption have to be taken with a grain of salt. The hard part is getting people to do that.
