He earned his doctoral degree from Louisiana State University in Clinical Psychology. Additionally, he completed a two-year fellowship in pediatric psychology from the University of Nebraska Medical School (UNMC). After serving as an in-patient psychologist at Southeast Louisiana Hospital's Developmental Neuropsychiatric Program for seven years, he became the Director of Behavioral Medicine for East Jefferson's Family Medicine Residency Program. Over the course of his career he has taught at several universities and hospitals, and has published his research in national journals. At the East Jefferson Family Practice Center, Dr. O'Callaghan works alongside the physicians to offer a combined approach to address a multitude of issues including depression, anxiety, grief, stress, sleep problems, and various pediatric developmental and behavioral issues.