We Know Plenty About Marijuana — It’s Time To Regulate It Accordingly

Photo by Marcobeltrametti via Wikimedia Commons.


by Paul Armentano

on April 1, 2015

A common refrain among proponents of continued cannabis criminalization is that there exists a dearth of science specific to the plant’s effects on consumers and society. This claim is woefully inaccurate.

Cannabis possesses an extensive history of human use dating back thousands of years, thus providing society with ample empirical evidence as to its relative safety and efficacy. Moreover, despite decades of politicization and prohibition, the marijuana plant is nevertheless one of the most studied biologically active substances of modern times. A search on PubMed, the repository for all peer-reviewed scientific papers, using the term “marijuana” yields more than 21,000 scientific papers referencing the plant and/or its constituents, nearly half of which have been published just within the past decade. By contrast, a keyword search using the term ‘ibuprofen’ yields only about half as many papers; a search associated with the prescription painkiller ‘hydrocodone’ yields only 700 studies, while a search using the key word ‘adderall’ yields fewer than 200 peer-reviewed papers.

Among this extensive body of cannabis-specific literature are well over 100 randomized controlled studies, involving thousands of subjects, evaluating the safety and efficacy of cannabis or individual cannabinoids. By comparison, a 2014 review in the Journal of the American Medical Association reports that the majority of FDA approved medications are legalized on the basis of only two pivotal trials. Marinol, an FDA-approved pill containing synthetic THC, was approved by the agency as an appetite stimulant on the basis of a single randomized trial involving some 139 participants.

A recent review of a series of California university sponsored clinical trials assessing the safety and therapeutic efficacy of whole-plant cannabis, published in The Open Neurology Journal, concludes, “Based on evidence currently available the Schedule I classification (for cannabis) is not tenable; it is not accurate that cannabis has no medical value, or that information on safety is lacking.” A separate 2015 review assessing the comparative safety of drug exposure determined cannabis to be safer than any other licit or illicit substance assessed.

What else do we know about cannabis? We also know that states possess the ability to regulate the plant effectively. Over twenty states and the District of Columbia allow for the physician-recommended use of cannabis and four additional states regulate the plant’s retail sale. To date, no state that has enacted such laws has taken steps to repeal them. Based on these statewide experiences, it is clear liberalized cannabis policies are associated with decreased crime and improved public health.

Contrary to critics’ claims, neither the imposition of statewide medical marijuana legalization nor the establishment of dispensaries is associated with increases in violent crimes, burglary, or property crimes, according to a pair of recently published scientific studies. A federally commissioned analysis appearing in the Journal of Studies on Alcohol and Drugs, determined that there are “no observed associations between the density of medical marijuana dispensaries and either violent or property crime rates.” Another study, published in 2014 in PLoS One, concluded that legalizing medical marijuana access at the state level “is not predictive of higher crime rates and may be related to reductions in rates of homicide and assault.”

Moreover, recent data published in the Journal of the American Medical Association Internal Medicine reports that the enactment of statewide medicinal marijuana laws is associated with significantly lower state-level opioid overdose mortality rates. Researchers concluded, “States with medical cannabis laws had a 24.8 percent lower mean annual opioid overdose mortality rate compared with states without medical cannabis laws.” Specifically, they found that overdose deaths from opioids decreased by an average of 20 percent one year after the law’s implementation, 25 percent by two years, and up to 33 percent by years five and six.

Is it accurate to say that we know everything there is to know about cannabis? Of course not. But at a minimum, we as a society know enough about cannabis to cease arresting adults who consume it responsibly.

Paul Armentano is the Deputy Director of NORML — the National Organization for the reform of Marijuana Laws — and also serves as a senior policy advisor for Freedom Leaf, Inc. He is the co-author of the book, Marijuana Is Safer: So Why Are We Driving People to Drink? (Chelsea Green, 2013).