Because marijuana is a Schedule I drug under the Controlled Substances Act, the therapeutic benefits of cannabis are no longer mentioned in the formal education of health care professionals. Doctors who do learn of the drug's therapeutic value are often intimidated by its illegal status. Thus millions of patients afflicted with such illnesses as glaucoma, AIDS, cancer, multiple sclerosis, spinal cord injuries, seizure disorders and chronic pain are denied access to information about the drug's benefits and, in many cases, suffer needlessly. Straightforward and nonpoliticized information on the therapeutic uses of cannabis is provided here by medical, legal and scientific professionals. Legal issues, a worldwide history of therapeutic cannabis and a discussion of its pharmacology are covered. Specific medical uses are then examined, including its application for sufferers of cancer, AIDS, glaucoma, and seizure disorders, and its potential use in psychiatry. Dosages and administration of cannabis are explored, along with considerations on the use of the drug during pregnancy and the risks of addiction and dependency.