Tell a highly uninformed person, who's still skeptical about medical marijuana, that you consume cannabis primarily to combat anxiety, and you'll likely encounter an eye-roll in reply. Since the condition is hard to physically substantiate and very commonly suffered, they assume anxiety is merely your “excuse” for smoking pot, rather than your valid medical reason. (As if you need a reason, an excuse, or anybody's permission, but that's another discussion).

Meanwhile, an estimated 20% of Americans will experience an anxiety disorder at some point in their lives. If they seek medical treatment, that will typically mean being prescribed highly addictive pharmaceutical drugs to treat their conditions, to the tune of billions of dollars in sales every year for the pharmaceutical companies, and nobody bats an eye. Including the many doctors steering their patients towards these dangerous pills without ever discussing a far safer herbal option.

But that might start to change now that a new international study, led by researchers at Vanderbilt University, has for the first time shown, in a mouse model, that the central nucleus of the brain's amygdala contains cannabinoid receptors. Key to sparking our “fight-or-flight” responses, as well as regulating anxiety, the amygdala is an emotional center in the brain that's vital to proper cognitive functioning. And when we encounter too much stress, our body's natural cannabinoid levels may not be sufficient to prevent debilitating anxiety, explaining why people chose to smoke pot to treat the condition.

According to Sachin Patel, M.D., Ph.D., a professor of Psychiatry, Molecular Physiology and Biophysics at Vanderbilt and the paper’s senior author, this study builds on previous science showing that the body's natural endocannabinoid system “regulates anxiety and the response to stress by dampening excitatory signals that involve the neurotransmitter glutamate.” For this new study, researchers used microscopy techniques to identify the cannabinoid receptors located in the amygdala and monitor their function.

“We know where the receptors are, we know their function, we know how these neurons make their own cannabinoids,” according Patel. “Now can we see how that system is affected by … stress and chronic (marijuana) use? [If so], that might fundamentally change our understanding of cellular communication in the amygdala.”

The full report was published in the journal Neuron, and included scientists from the Hungarian Academy of Sciences in Budapest, Hokkaido University in Sapporo, Japan, and Indiana University in Bloomington.