Strassman's studies investigated the effects of N,N-dimethyltryptamine (DMT), a powerful entheogen, or psychedelic, that he hypothesizes is produced by the human brain in the pineal gland. DMT is found naturally in various natural sources, and is related to human neurotransmitters such as serotonin and melatonin. Strassman refers to DMT as the "god molecule" or "spirit molecule". During the project's five years, he administered approximately 400 doses of DMT to 60 human volunteers. This research took place at the University of New Mexico's School of Medicine in Albuquerque, New Mexico where he was then tenured Associate Professor of Psychiatry. Dr. Strassman has conjectured that when a person is approaching death, the pineal gland releases DMT, accounting for much of the imagery reported by survivors of near-death experiences. However he has not provided any explanation for the mechanism by which this synthesis could produce levels of DMT that would lead to such effects and the theory is not accepted by others in the field of neurochemistry due to the absence of supporting evidence (i.e. a plausible synthesis mechanism or actual evidance that DMT is found in the body under these circumstances). It should also be noted that DMT is released on the forty-ninth day of fetus development, something Dr. Strassman has attributed to being the beginning of the soul. The necessary constituents (see methyltransferases) needed to make DMT are found in the pineal, although the enzyme's stereo-specificity only allows for the conversion of serotonin to melatonin and vice versa. He wrote about the research program in his book DMT: The Spirit Molecule, and a documentary movie based on this book is currently in production. Dr. Strassman has also conducted similar research using psilocybin, a psychedelic alkaloid found in hallucinogenic mushrooms.

• Rick Strassman (with Slawek Wojtowicz, Luis Eduardo Luna and Ede Frecska), "Inner Paths to Outer Space: Journeys to Alien Worlds through Psychedelics and Other Spiritual Technologies" , 376 pages, Park Street Press, 2008, ISBN 978-1594772245

• Rick Strassman, DMT: The Spirit Molecule: A Doctor's Revolutionary Research into the Biology of Near-Death and Mystical Experiences, 320 pages, Park Street Press, 2001, ISBN 0-89281-927-8

• Rick Strassman, Hallucinogens (chapter), in Mind-Altering Drugs: The Science Of Subjective Experience, 402 pages, Oxford University Press, 2005, ISBN 0-19-516531-4