Dr. Gabriella Nissan earned her Bachelor of Arts in Psychology from Barnard College at Columbia University. She graduated from Hofstra University with a Master of Science and a Doctor of Psychology (Psy.D.), both in School-Community Psychology. Her clinical training was completed across a variety of settings, including community clinics, schools, and psychiatric hospitals.

Dr. Nissan's clinical externship training took place at Jamaica Hospital Medical Center, where she provided treatment to a diverse population of patients experiencing serious mental illness in both in-patient and out-patient settings. She completed a postdoctoral fellowship at Blue Anchor Psychology, a private practice in New York City, where she received specialized training in couples therapy and sex therapy. She then continued working at the group practice for several years before opening her own private practice.