British scientists have unraveled how a nonintoxicating component of cannabis acts in key brain areas to reduce abnormal activity in patients at risk of psychosis, suggesting the ingredient could become a novel anti-psychotic medicine.

While regular use of potent forms of cannabis can increase the chances of developing psychosis, the chemical cannabidiol, or CBD, appears to have the opposite effect.

CBD is the same cannabis compound that has also shown benefits in epilepsy, leading in June to the first U.S. approval of a cannabis-based drug, a purified form of CBD from GW Pharmaceuticals.