I Grow My Own in The Brain, Thank You: Endocannabinoids and Marijuana

Neuroscience_Neurology.jpgA researcher at the University of Buffalo’s Institute of Addictions won a five year, $1.7 million grant from the National Institutes of Health (NIH) to investigate the role of “endocannabinoids” (the brain’s own marijuana) in combating stress and anxiety, an integral part of modern lifestyles. The study, as recently revealed on the University of Buffalo’s website, is an attempt to address one of the most widely acknowledged reasons why people abuse marijuana worldwide — to relieve stress.

However, because of its addictive potential, marijuana cannot be clinically used in the treatment of stress related mood disorders, for example, anxiety. But this study could open the doors to a harmless and more cost-effective way to deal with this problem — using the brain’s own source of marijuana-type molecules, the endocannabinoids.

Research into endocannabinoids (ECs) is a relatively recent development over the last decade, and it is known that they affect a vast array of interlinked body systems, with EC receptors found in the brain, gastro-intestinal tract, and fat cells. For instance, it has been widely reported that the EC system in our brain makes us feel hungrier and increases our food intake. In the muscles, EC over-activity causes resistance to insulin, leading to a diabetes-type condition; while in the fat cells, it leads to over production of triglycerides and accumulation of body fat. Several drugs designed to block EC receptors are in the pipeline, or seeking FDA approval for the fight against obesity.

ECs have also been implicated in tobacco addiction, through the effect of nicotine on the brain’s limbic system leading to the release of huge amounts of ECs. Smoking might be used for stress relief for pretty much the same reason as marijuana, although it has historically been more “socially acceptable.” In fact Rimonabant, the first prototype EC-blocker, is promising for both weight loss and smoking cessation, and although approved in the European Union, is awaiting approval from the US FDA.

At a more fundamental level perhaps, ECs are part of the body’s “reward and pleasure” system in the brain, and could perhaps hold the clue to why some of us indulge in “emotional overeating” while under stress, and put on more weight. In the future selective EC receptor agonists or blockers could be used to suppress appetite on one hand or relieve stress on the other, without the necessity for the two effects to be linked together.

It might also put an end to cannabis abuse for a large proportion of users who rely on it for stress relief.


Xie S, Furjanic MA, et al. The endocannabinoid system and rimonabant: a new drug with a novel mechanism of action involving cannabinoid CB1 receptor antagonism–or inverse agonism—as potential obesity treatment and other therapeutic use. J Clin Pharm Ther. 2007 Jun;32(3):209-31.

Sudip Ghosh, MD

Sudip Ghosh, MD, is a surgeon at the University of Manchester, UK and a medical writer.
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