Weiss graduated from the Yale University School of Medicine in 1970, completing an internship in internal medicine at the New York University Medical Center then returning to Yale for a two-year residency in psychiatry.
As a traditional psychotherapist, Dr. Brian Weiss was astonished and skeptical when one of his patients began recalling past-life traumas that seemed to explain her symptoms. He changed his views when she began to channel messages from "the space between lives," which contained revelations about Dr. Weiss's family and his son that had passed away. Using past-life therapy, he was able to cure the patient and embark on a new, more meaningful phase of his own career.