Researchers have discovered a new drug that raises the level of endocannabinoids--the 'brain's own cannabis'--providing anti-depressant effects. The new research published in this week's Proceedings of the National Academy of Sciences (PNAS), suggests the new drug, called URB597, could represent a safer alternative to cannabis for the treatment of pain and depression, and open the door to new and improved treatments for clinical depression--a condition that affects around 20% of Canadians.

In preclinical laboratory tests researchers found that URB597 increased the production of endocannabinoids by blocking their degradation, resulting in measurable antidepressant effects. "This is the first time it has been shown that a drug that increases endocannabinoids in the brain can improve your mood," says the lead investigator Dr. Gabriella Gobbi, an MUHC and Université de Montréal researcher.

Endocannabinoids are chemicals released by the brain under certain conditions, like exercise; they stimulate specific brain receptors that can trigger feelings of well-being. The researchers, which included scientists from the University of California at Irvine, were able to measure serotonin and noradrenaline activity as a result of the increased endocannabinoids, and also conducted standard experiments to gauge the 'mood' of their subjects and confirm their findings.

"The results were similar to the effect we might expect from the use of commonly prescribed antidepressants, which are effective on only around 30% of the population," explains Dr. Gobbi. "Our discovery strengthens the case for URB597 as a safer, non-addictive, non-psychotropic alternative to cannabis for the treatment of pain and depression and provides hope for the development of an alternate line of antidepressants, with a wider range of effectiveness."

Cannabis has been known for its anti-depressant and pain-relief effects for many years, but the addictive nature and general health concerns of cannabis use make this drug far from ideal as a medical treatment. The active ingredient in cannabis--THC (Tetrahydrocannabinol)--stimulates cannabinoid receptors.

Funding for this study was provided by the Fonds de la Recherche en Santé du Québec (FRSQ), the Canadian Psychiatric Research Foundation (CPRF), the National Institute on Drug Abuse (NIDA) and an MUHC fellowship.