What is cannabis?

By Josh Kaplan, Ph.D.

Cannabis is a flowering plant that produces many chemicals, called cannabinoids, that have been used for recreational and therapeutic benefits. Cannabis is now used to describe any of the cannabinoids naturally produced by the plant. The high-inducing chemical, THC, and medicinally-relevant CBD are the most well-studied, but science is revealing medicinal benefits of other cannabinoids like CBN, THCV, and CBG. Optimal therapeutic benefits may be achieved with a combination of many cannabinoids and the aromatic terpenes they’re dissolved in.  

The term “cannabis” is short for the plant’s scientific taxonomical name, Cannabis sativa. For centuries, people used “cannabis” to describe the plant they used for medicinal and recreational purposes. It wasn’t until the 1930’s that “marijuana” entered the American vernacular. Marijuana and cannabis are the same thing, but powerful voices in the media and the federal government deliberately used the term “marihuana”, the slang name used among Mexican immigrants, in their smear campaign against the plant. Motivated by racial prejudice, xenophobia, and money, marijuana came to represent violence and hysteria. All this while many used cannabis for medicinal purposes! Those who had been consuming cannabis for medicinal reasons lost access when the federal government passed legislation restricting its possession. Over 80 years later, people are rediscovering cannabis’ wellness benefits. Scientific advancement has led to the optimization of its medicinal potential. In doing so, we’ve ditched the racially-tinged marijuana, and returned to cannabis with its medicinally-based roots.

The cannabis plant contains numerous terpenes, which give the flower a distinctive odor and flavor. Dissolved in these terpenes are over 100 chemicals, called cannabinoids, many of which act on the brain and body to deliver both recreational and therapeutic benefits. Cannabinoid composition ranges across strain, which makes some better for recreational purposes (i.e., getting high) and others for therapeutic benefits.

Two of the most well-studied cannabinoids are D9–tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is the main chemical responsible for the “high” that’s sought by recreational users. The average THC levels of over the last couple decades have tripled1, driven by those seeking an increasingly stronger high. This increase in THC often comes at the expense of CBD, which can counteract many of THC’s effects2 and conveys many of cannabis’ therapeutic benefits3. As a result, there’s been a growing divergence in cannabis use as people can now get higher than ever, while others take advantage of optimized cannabinoid concentrations for health and wellness purposes.

So when talking about cannabis, cannabinoid composition is important! It’s practically meaningless to say that someone uses cannabis without saying what’s in it. Someone who smokes high-THC strains is going to have a vastly different psychological experience, be subject to distinct side effects, and bear a unique health burden than someone using a more balanced strain or a CBD-rich preparation. Yet, most of the large epidemiological studies of cannabis’ impact on health and society fail to identify THC levels and cannabinoid composition in their assessment. This makes it especially difficult to interpret any of these large population studies.

Because of the research hurdles placed by the federal government, it’s challenging to study cannabis in a controlled laboratory environment, especially in humans. Instead, we rely on small cohort humans studies and turn to mice and rats to gain mechanistic insight into how different cannabinoids affect the brain.

Despite these research challenges, we’ve been gaining remarkable insight into the therapeutic benefits of cannabis and its brain mechanisms ever since THC was discovered in 19644. The information presented on this site is an overview of this exciting research. As more information continues to be published, we will strive to update our pages with the most up-to-date and relevant cannabis science.

Summary: Cannabis has been used for centuries for its therapeutic potential, but a coordinated media and governmental attack on cannabis has led to federal restrictions that has prevented access and stigmatized its use. Marijuana and cannabis are synonymous terms, but cannabis is the preferred all-encompassing term for the plant-based chemicals, called cannabinoids, that have recreational and therapeutic benefits. The effects of cannabis depend on its cannabinoid composition. THC is the primary high-inducing cannabinoid, and the more THC, the stronger the high. Cannabis’ therapeutic benefits are often improved by a more balanced composition of THC and CBD. Scientists are better understanding how the combination of multiple cannabinoids and terpenes enhance cannabis’ therapeutic benefits.

1 ElSohly, M. A. et al. Changes in Cannabis Potency Over the Last 2 Decades (1995-2014): Analysis of Current Data in the United States. Biol Psychiatry 79, 613-619, doi:10.1016/j.biopsych.2016.01.004 (2016).
2 Niesink, R. J. & van Laar, M. W. Does Cannabidiol Protect Against Adverse Psychological Effects of THC? Front Psychiatry 4, 130, doi:10.3389/fpsyt.2013.00130 (2013).
3 Mechoulam, R., Peters, M., Murillo-Rodriguez, E., & Hanus, L.O. . Cannabidiol – Recent Advances. Chemistry & Biodiversity 4, 1678-1692 (2007).
4 Gaoni, Y. & Mechoulam, R. Isolation, Structure, and Partial Synthesis of an Active Constituent of Hashish. Journal of the American Chemical Society 86, 1646-1647