The Department of Psychiatry has played an important role in the development of Stony Brook's School of Medicine and University Hospital. The Department of Psychiatry was the first Department to be organized at the School of Medicine. Under the leadership of the late Stanley Yolles, who came to Stony Brook following his tenure as Director of the NIMH, the Department reflected Dr. Yolles' interest in Social Psychiatry. Although a young department, it quickly gained international stature, particularly in areas like electroconvulsive therapy (Max Fink, M.D.) and human sexual behavior (Richard Green, M.D., Joseph LoPiccolo, Ph.D.). In the early days of the department (pre-University Hospital) the clinical training sites were at Hillside Hospital, Nassau County Medical Center, and Central Islip Psychiatric Center. The early 1980's saw the opening of University Hospital and the recruitment and hiring of the Department's second Chair, Fritz Henn, PhD, MD. Dr. Henn was recruited from the University of Iowa to lead the Department into the era of the neurosciences. The current Chair, Mark Sedler, MD, MPH, has focused on expanding the clinical services and research breadth of the department, as well as steering the department through this very challenging period for academic medicine and psychiatry.

University Hospital opened its doors to the people of Suffolk County and the rest of Long Island in 1979. Before that time, residents received clinical training at the Central Islip Psychiatric Center, Nassau County Medical Center and Hillside Hospital. Since 1979, the clinical programs of the Department of Psychiatry have been located at University Hospital and the Northport Veterans' Administration Medical Center.