Professor Harriet de Wit, a pioneering researcher in psychoactive drugs at the University of Chicago, shares her remarkable 45-year scientific journey in this illuminating Genomic Press Interview. As Director of the Human Behavioral Pharmacology Laboratory and recipient of prestigious honors including the 2019 European Behavioral Pharmacology Society Distinguished Investigator Award, Dr. de Wit has revolutionized our understanding of how drugs like MDMA and LSD affect human behavior and consciousness. Her groundbreaking research, continuously funded by the National Institutes of Health for over 42 years—an extraordinary achievement in scientific excellence—has revealed crucial insights into the therapeutic potential of psychedelics and their effects on social connection, empathy, and neural function. Most recently, her laboratory demonstrated that MDMA enhances feelings of social connectedness during interpersonal interactions, findings that have profound implications for PTSD treatment and psychotherapy. As the expert consulted by renowned authors like Michael Pollan to understand psychedelic neuroscience, Dr. de Wit bridges the critical gap between animal research and human studies, using pioneering methodologies to translate behavioral observations across species. Her innovative work on microdosing, place preference procedures, and drug-induced neural actions has established new paradigms in addiction science and psychiatric treatment. She served as Field Editor for Psychopharmacology and Deputy Editor for Alcoholism: Clinical and Experimental Research for many years. Throughout her career, Dr. de Wit mentored numerous post-doctoral fellows and graduate students. Her life's work has been defined by curiosity, patience, and scientific rigor, first acquired as a graduate student from her advisor, Jane Stewart, at Concordia University. From her roots in Canada, Dr. de Wit went on to become one of the world's foremost authorities on psychopharmacology.