Marijuana Research Has Increased Exponentially in Recent Years, Review Finds

Researchers conducted over 29,000 cannabis-related scientific studies between 2000 and 2017.

The amount of research into cannabis and its therapeutic potential has increased exponentially since 2000, according to a new research review published in the journal Population Health Management.

A research team based in Israel used online research databases PubMed and Web of Science to assess the trends in the publication of marijuana-related studies from 2000 to 2017.

They found that the number of cannabis-related studies increased significantly over the 17-year period, with a sharp spike beginning in 2013.

The increase in cannabis-related research outpaced that of scientific research as a whole. While the overall annual number of scientific publications increased 2.5 times between 2000-2017, from 531,664 to 1,282,220, the number of publications focused on cannabis increased 4.5 times, from 620 to 2,388.

The number of studies focused on medical cannabis increased nine times over the 17 years, from 82 in 2000 to 742 in 2017.

“The results of the present study demonstrate an ongoing increase in the number of publications related to cannabis in general and to medical cannabis in particular,” the researchers wrote in the study. “The spike in medical publications on medical cannabis that began in 2013 is impressive and encouraging.”

Studies That Were Done

Overall, the researchers identified just over 29,000 cannabis-related scientific studies published over the 17 years, with over 3,3000 of those focused on medical marijuana. The most significant increase in the number of publications was related to the field of psychiatry.

Of the studies focused on medical cannabis, most investigated its use in the treatment of HIV, chronic pain, multiple sclerosis, nausea, and epilepsy. Between 2011-2013, there was a significant increase in the number of studies looking into cannabis’ effects in the fields of neurology and cancer treatment.

Since 2013, there has been a significant rise in the number of studies looking into the effects of cannabis in children and the elderly.

Over 60 percent of the studies were considered “original research,” and 66 percent came from researchers in the United States.

Impact of Legalization

The researchers note that the recent uptick in marijuana research appears to correlate to state-level legalization efforts. Twenty-five states have legalized medical marijuana since 2000, bringing the nation’s total to 30. Additionally, since 2012, nine states have legalized recreational marijuana.

“The absence of an increase in publications on cannabis until recent years would appear to be related to the United Nations Single Convention that prohibited the use of cannabis for recreational purposes and had broad support in most of the developed countries,” the researchers explain in the study.

“It is noteworthy that the significant growth in the number of publications on medical cannabis since 2013 parallels legislation permitting the use of recreational cannabis in the states of Washington and Colorado in 2012 and in Alaska and Oregon in 2014, and subsequently in many other countries around the world,” they added.

Under federal law, cannabis remains classified as a Schedule I substance. The category is reserved for substances with a high potential for abuse and no currently accepted medical use in treatment in the U.S.

In response to the study’s findings, NORML’s Deputy Director Paul Armentano said: “These results stand in stark contrast to the popular narrative that we lack adequate scientific understanding of cannabis and its effects. In fact, ample studies already exist to contradict cannabis’ federal, schedule I status as a substance without medical utility, lacking acceptable safety, and possessing a high potential of abuse.”

“More clinical research is welcome, but unfortunately science has never driven marijuana policy. If it did, the United States, would already have a very different policy in place,” he added.

You can access the full text of the new review, “Trends in Publications on Medical Cannabis from the Year 2000,” by visiting Mary Ann Liebert, Inc.

Studies on Cannabis

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