Psychedelic substances present in nature have been used by humans for hundreds of years to produce mind-altering changes in thought, mood, and perception - changes we do not experience otherwise except rarely in dreams, religious exaltation, or psychosis. Scientists in the 1950s and 1960s studied the practical and therapeutic uses for hallucinogens, including LSD and mescaline. But subsequently governments banned all human consumption of hallucinogens, thus putting a stop to the research. Recently, however, the Food and Drug Administration in the U.S. lifted the ban on scientific testing of these substances using human subjects. In these groundbreaking volumes, top researchers explain the testing and research underway to use - under the guidance of a trained provider - psychedelic substances for better physical and mental health. Experts including physicians and psychiatrists show how psychedelic substances may alleviate symptoms or spur cures for disorders from AIDS to arthritis to post traumatic stress disorder. Spiritual uses are also addressed and the perceived benefits described. Medical and legal issues for therapeutic uses are also presented. The psychedelic drugs explained in these pages for potential health use include: LSD; Ayahuasca; Psyilocybin; Peyote; MDMA/Ecstasy; and Marijauana. Appendices list a sample of sites where medical research with psychedelics is underway, and describe prominent advocates and organizations pushing to further this research.