Marijuana contains many cannabinoid-based compounds, including delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD).  Recent Internet ads have made claims that “CBD can cure arthritis, multiple sclerosis, chronic pain, schizophrenia, and [most recently] epilepsy.”  Somehow one particular component of marijuana plant has become much more popular than all of the sixty (at least) other biologically active molecules that have been isolated from this plant.  Cannabidiol is the main non-psychotropic cannabinoid present in the Cannabis sativa plant.  Both CBD and THC are capable of interacting with the complex variety of receptor proteins that exist in the human brain.  However, they do not do so with the same degree of effectiveness.  To date, all of the positive evidence supporting the use of medical marijuana in humans has come from studies of the entire plant or experimental investigations of THC.  A recent study published in the Journal of Neuroscience (4 May 2016, 36(18): 5160-5169) has shown CBD has significant therapeutic efficacy for the treatment of schizophrenia.  These scientists have also identified where CBD likely acts in the brains of schizophrenics, the nucleus accumbens (the brain’s primary pleasure center), and how it is able to produce effects similar to standard antipsychotic medications. 

This discovery stands in stark contrast to previous claims that marijuana induces psychosis.  Overall, today’s scientists are being more open-minded about the benefits of marijuana and are trying to bring less bias to their investigations.  One recent study asked whether marijuana use was associated with an earlier age of onset for the first episode of schizophrenia.  The researchers concluded that there was no significant relationship between the onset of illness and marijuana use that could not be accounted for by other demographic and clinical variables.  Meaning, once again it is important to take notice of all of the other variables that contribute to developing psychosis.

Recent studies have also demonstrated that the endogenous marijuana receptors in the brain of someone with schizophrenia respond differently than those in the brain of someone without a predisposition to this disorder. This recent report now documents that a safe, non-psychoactive component of marijuana may be able to trigger the same molecular signaling pathways associated with the effects of classic antipsychotic medications.  The evidence supporting the use of medical marijuana continues to become more compelling. 

© Gary L. Wenk, Ph.D. Author of “Your Brain on Food,” 2nd Ed, 2015 (Oxford University Press); TED talk:

Marijuana and Coffee are Good for the Brain

You are reading

Your Brain on Food

Are Your Medications Giving You Nightmares?

It's amazing that most of us do not experience a nightmare every night.

Is a Vegetarian Diet Always Healthy?

For many people the answer is "no;" this is why.

How a Suicide Attempt Can Affect the Brain

Understanding what happens in the brain may lead to better therapies