Perry N. Halkitis, PhD, MS, MPH, is Professor of Applied Psychology and Public Health (Steinhardt School), and Population Health (Langone School of Medicine), Director of the Center for Health, Identity, Behavior and Prevention Studies, and Associate Dean at New York University. Dr. Halkitis' program of research examines the intersection between the HIV epidemic, drug abuse, and mental health burden in LGBT populations, and he is well known as one of the nation's leading experts on substance use and HIV behavioral research. Dr. Halkitis holds degrees in both psychology and public health.