LONDON, Ont. - With Cannabis now legal and on the market, researchers at Western University have been looking at how THC, the main psychoactive chemical in cannabis, and cannabidiol (CBD) together effect the brain.

It has been previously shown that strains of cannabis with high levels of THC and low levels of CBD can cause increased psychiatric effects, including paranoia, anxiety and addictive-behaviours, but why that was occurring was not fully understood.

Dr. Steven Laviolette at the Schulich School of Medicine and Dentistry and his research team used rats to investigate the role of a molecule in the brain’s hippocampus called extracellular-signal regulated kinase (ERK) which triggers the neuropsychiatric effects of THC.

For the first time ever the findings have shown that there are molecular mechanisms by which CBD may block the THC-related side effects.

Laviolette says the findings have important implications for prescribing cannabis and long-term cannabis use.

For example, for individuals more prone to cannabis-related side effects, it is critical to limit use to strains with high CBD and low THC content.

The full study can be found here.