Cannabinoids and the Brain introduces an informed general audience to the scientific discovery of the endocannabinoid system and recent preclinical research that explains its importance in brain functioning. The endocannabinoids, anandamide and 2-AG, act on the same cannabinoid receptors, that are activated by the primary psychoactive compound found in marijuana, Δ9-tetrahydrocannabinol (THC). Therefore, the scientific investigations of the functions of the endocannabinoid system are guided by the known effects of marijuana on the brain and body. The book reviews the scientific evidence of the role that the endocannabinoid system plays in regulating emotion, anxiety, depression, psychosis, reward and addiction, learning and memory, feeding, nausea/vomiting, pain, epilepsy, and other neurological disorders. Anecdotal reports are linked with the current scientific literature on the medicinal benefits of marijuana. Cannabis contains over 80 chemicals that have closely related structures, called cannabinoids, but the only major mood-altering constituent is THC. Another major plant cannabinoid is cannabidiol (CBD), which is not psychoactive; yet, considerable recent preclinical research reviewed in various chapters reveals that CBD has promising therapeutic potential in treatment of pain, anxiety, nausea and epilepsy. Only recently, has research been conducted with some of the other compounds found in cannabis. The subject matter of the book is extremely timely in light of the current ongoing debate not only about medical marijuana, but also about its legal status.