Grof is known for his early studies of LSD and its effects on the psyche—the field of psychedelic psychotherapy. Building on his observations while conducting LSD research and on Otto Rank's theory of birth trauma, Grof constructed a theoretical framework for pre- and perinatal psychology and transpersonal psychology in which LSD trips and other powerfully emotional experiences were mapped onto one's early fetal and neonatal experiences. Over time, this theory developed into an in-depth "cartography" of the deep human psyche. Following the legal suppression of LSD use in the late 1960s, Grof went on to discover that many of these states of mind could be explored without drugs by using certain breathing techniques in a supportive environment. He continues this work today under the title "Holotropic Breathwork". Grof received his M.D. from Charles University in Prague in 1957, and then completed his Ph.D. in Medicine at the Czechoslovakian Academy of Sciences in 1965, training as a Freudian psychoanalyst at this time. In 1967, he was invited as an Assistant Professor of Psychiatry at Johns Hopkins University School of Medicine in Baltimore, United States, and went on to become Chief of Psychiatric Research at the Maryland Psychiatric Research Center where he worked with Walter Pahnke and Bill Richards among others. In 1973, Dr. Grof was invited to the Esalen Institute in Big Sur, California, and lived there until 1987 as a scholar-in-residence, developing his ideas. Being the founding president of the International Transpersonal Association (founded in 1977), he went on to become distinguished adjunct faculty member of the Department of Philosophy, Cosmology, and Consciousness at the California Institute of Integral Studies, a position he remains in today. Grof was featured in the film Entheogen: Awakening the Divine Within, a 2006 documentary about rediscovering an enchanted cosmos in the modern world.