A study conducted by Volteface, a London-based policy think tank seeking to improve safety of marijuana use through legalization, found extremely high levels of tetrahydrocannabinol (THC) in samples taken from the streets of Manchester. According to researchers, too much THC, the psychoactive component of pot that creates the “high,” combined with very small amounts of cannabidiols (CBDs), the protective part that prevents marijuana from becoming unsafe, can cause psychiatric issues, including addiction and memory problems.
“High-potency pot is causing psychiatric issues, including addiction and memory problems… [and] the riskiest pot is coming from the black market—which could be an argument for expanding legalization,” says Firger.
THC and CBD come from the same part of the plant, so more of one component means less of the other. According to some recent research, people using strains pot that is also high in CBD are less likely to have mental health issues than those who smoke strains with low CBD but high THC content.