Dr. John W. Cassidy is certified by the American Board of Psychiatry and Neurology and brings more than 30 years of experience in clinical neuroscience and neurobehavioral rehabilitation. Founder of Nexus Health Systems in 1992, he currently serves as Executive Chairman. Earlier in his career, he was Psychiatrist-in-Charge and Co-Founder of the Neuropsychiatry Program at McLean Hospital; Chief Medical Officer and Founder of the Neurobehavioral Institute of Houston; Director and Founder of the Neuropsychiatry Subspecialty Services of Del Oro Rehabilitation Hospital; and Medical Director of Neurobehavioral Programs at Cypress Creek Hospital.

Dr. Cassidy has dedicated his career to advancing treatment for individuals with acquired and traumatic brain injuries. His comprehensive rehabilitative model addresses interpersonal, behavioral, cognitive, physical, and emotional needs to support successful recovery and long-term outcomes.

He earned a Bachelor of Arts from Hiram College and a Doctor of Medicine from the University of Cincinnati College of Medicine. He completed postgraduate training at Harvard Medical School and has spoken nationally and internationally on the sequelae and management of severe traumatic brain injury. He is the author of three books and numerous papers, book chapters, and editorials.