In the scientific literature, 'skunk' has come to mean something more specific: cannabis that contains a high percentage of Tetrahydrocannabinol (THC, the intoxicating part) but little to no Cannabidiol (CBD, an antipsychotic), in contrast to other milder ‘strains’ which contain lower levels of THC and more a significant CBD component. Skunk is a deliberate creation of the illicit industry, fashioned by generations of selective breeding and advanced cultivation methods that have steadily pushed THC levels up over the last 20 years.