The International Association for Cannabinoid Medicines, an international non-profit cannabinoid association, wrote in its "Cannabidiol" page on the website (accessed Sep. 28, 2011):

“CBD, or cannabidiol, is the major non-psychotropic cannabinoid found in Cannabis. It has shown anti-epileptic, anti-inflammatory, anti-emetic, muscle relaxing, anxiolytic, neuroprotective and anti-psychotic activity and reduces the psychoactive effects of THC [D9-tetrahydrocannabinol, the primary psychoactive ingredient in marijuana]. The mode of action of cannabidiol is not fully understood and several mechanisms have been proposed…”

Sep. 28, 2011