“Tetrahydrocannabinol (THC) is the main psychoactive substance in cannabis. Cannabidiol (CBD) is a cannabinoid that appears in cannabis resin but rarely in herbal cannabis. In recent years, many positive attributes have been ascribed to CBD. Is cannabis that contains CBD less harmful than cannabis without CBD? Are people who smoke cannabis resin, therefore, less susceptible to psychosis or less likely to become addicted than are people who smoke herbal marijuana?
Delta-9-tetrahydrocannabinol (THC) is the main psychoactive constituent of cannabis, and most, if not all, of the effects associated with the use of cannabis are caused by THC. Recent studies have suggested a possible protective effect of another cannabinoid, cannabidiol (CBD).
Most recreational users will never be faced with persistent mental illness, but in some individuals cannabis use leads to undesirable effects: cognitive impairment, anxiety, paranoia, and increased risks of developing chronic psychosis or drug addiction.
Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC.
Few or no adverse effects of CBD have been proffered, and where CBD has been found to have an effect, it is usually in a “positive” (i.e., salubrious) direction. The evidence favoring a beneficial effect of CBD therefore merits further investigation in studies in which the amounts and ratios of CBD and THC correspond to the daily practices of recreational cannabis use.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797438/
“Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC.” https://www.ncbi.nlm.nih.gov/pubmed/24137134
“CBD may also potentiate some of Δ9-THC’s beneficial effects as it reduces Δ9-THC’s psychoactivity to enhance its tolerability and widen its therapeutic window.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4707667/