Dr. Ethan Russo’s Take on CBD: Common Misconceptions

Written by Colby McCoy

Cannabidiol, or CBD, has become something of a sensation and enigma for consumers and researchers alike.

For one, the phytocannabinoid has been lauded for its benefits in treating conditions like epilepsy; however, many companies developing CBD products often make claims not backed by solid science. These claims have even led to Warning Letters from the US Food & Drug Administration. Despite this, widespread misinformation associated with CBD abounds and has become a serious issue.

In a review from a few years ago, renowned neurologist and cannabis researcher Ethan Russo, MD dispelled multiple misconceptions that continue to impact the industry today. [1] We’ll cover a few key points he reviewed here:

“Non-psychoactive.” A common description of CBD includes the terms “non-psychoactive” or “non-psychotropic,” i.e. it has zero impact on one’s mental faculties. Dr. Russo instead raises the point that CBD possesses pharmacological properties to treat various mental conditions, including schizophrenia, addiction, and possibly depression. How could it be non-psychoactive while exerting these effects? Thus, a more accurate way of labeling CBD would be to say it is “non-intoxicating.”

Sedating. Another common misconception is that CBD is a sedative and will lull you to sleep. “Numerous modern studies, even those with single doses of 600 mg of oral CBD, in normal subjects have been free of sedative effects,” noted Dr. Russo.

That said, Dr. Russo also points out that “Epidiolex® (…cannabis extract with traces of THC, other cannabinoids, and terpenoids) employed in very high doses of 25 mg/kg/day or more” has produced sedative effects when taken with other medications. Essentially, CBD isolate alone (without calming terpenes) should not cause sleepiness.

Inverse Antagonism. CBD was once thought to block activity of the cannabinoid 1 (CB1) receptor as an inverse antagonist. Rimonabant, a synthetic CB1 antagonist, was marketed in Europe to treat obesity and metabolic symptoms. However, rimonabant was pulled from the market due to serious adverse events, such as suicidal ideation. CBD users do not normally experience these types of reactions.

This case instead suggested a different mechanism of action for CBD–what Dr. Russo described as “negative allosteric modulation” of CB1. This means that instead of fully blocking receptor activity, CBD changes the way the receptor responds to another famous cannabinoid called tetrahydrocannabinol, or THC.

Dr. Russo concluded with a call to cannabis researchers:

“It is incumbent upon the scientific and medical communities to understand better the mechanisms of action of CBD, its limitations, and particularly the myths and misconceptions that its meteoric rise in popularity have engendered.”

We couldn’t agree more!

Image Credit: Herbadea Berlin

Image Source: https://unsplash.com/photos/bcXNMT0i54s


  1. Russo EB. Cannabidiol claims and misconceptions. Trends in Pharmacological Sciences. 2017;38(3):198-201.

About the author

Colby McCoy

Colby McCoy is a recent graduate of the University of Georgia who has written for non-profits, marketing firms, and personal blogs. When not writing he can be found trekking the mountain ranges around Seattle, WA, with his two pups Harry and Riley.