The Department of Epidemiology at Columbia University has a worldwide research network spanning over 60 countries and faculty experts who are leaders in a variety of scientific research units. Chronic Disease Epidemiology Addresses the etiology, prevention, distribution, natural history, and treatment of chronic health disorders such as cancer and cardiovascular disease. Environmental Epidemiology Investigates exogenous risk factors and associated outcomes with a focus on transforming environments to improve health. Infectious Disease Epidemiology Encompasses domestic and global work on the recognition, transmission, and prevention of emerging and re-emerging communicable diseases. Injury Epidemiology Aims to improve population health by reducing death and disability from trauma and injuries such as motor vehicle crashes, gun violence, and suicide. Psychiatric/Neurologic Epidemiology Investigates the causes, progression, consequences, and prevention of psychiatric disorders, mental illness, and neurological disorders. Social Epidemiology Seeks to understand and intervene upon social, psychological, political, cultural, and economic circumstances that influence health. Substance Abuse Epidemiology Addresses the etiology, prevention, distribution, natural history, and treatment of substance use disorders, including and not limited to alcohol, marijuana, and opioids. Epidemiology Centers Department faculty lead a wide range of renowned research centers and programs at Columbia and around the world.