CNS Drug Reviews, Volume 5, No. 1, Spring 1999

Historically, the products of Cannabis sativa (or marijuana) have been used in socioreligious rites and for medicinal and recreational purposes. Multiple medical purposes, related or not to religious rituals, were prevalent in the ancient world (Assyria, Egypt, Rome, Greece and China) and India (54). Marijuana was used less widely in Western Europe and North America (54,55). Because reliable clinical effects were not always obtained and there were no experimental and/or clinical studies to support its medical benefits, the medicinal use of marijuana declined in Europe and North America (54). Since then, its usage as a recreational psychotropic drug began to increase at the beginning of the 1900s and was one factor that led to the enactment of the Harrison Narcotic Act in the Unted States during 1930s. In the 1970s, the use and abuse of marijuana, especially among adolescents, emerged worldwide. Today this plant and its products remain among the most frequently used psychoactive drugs in the world. Despite the widespread sociolegal controversy concerning the use and legalization of marijuana (5), the results of several animal and clinical studies strongly suggest that the cannabinoids may have valid medical applications (5,90) as antiemetics in the treatment of nausea associated with cancer chemotherapy, appetite stimulants for patients with AIDS or with severe cancer-related anorexia, analgesics in morphine-resistant pain, and agents to reduce intraocular pressure in the treatment of glaucoma (4,54,90). Controlled clinical trials were recently initiated in United Kingdom to evaluate the efficacy of cannabis and ∆9-tetrahydrocannabinol (∆9-THC) as treatments for spasticity in patients with multiple