Isolation and structure elucidation of most of the major cannabinoid constituents – including Δ9-tetrahydrocannabinol (Δ9-THC), which is the principal psychoactive molecule in Cannabis sativa – was achieved in the 1960s and 1970s. It was followed by the identification of two cannabinoid receptors in the 1980s and the early 1990s and by the identification of the endocannabinoids shortly thereafter. There have since been considerable advances in our understanding of the endocannabinoid system and its function in the brain, which reveal potential therapeutic targets for a wide range of brain disorders.