Ezra Susser, MD, DrPH, is Professor of Epidemiology and Psychiatry at the Mailman School of Public Health at Columbia University, and at New York State Psychiatric Institute. He is Director of the Imprints Center for Genetic and Environmental Life course Studies. Dr. Susser’s work, at present, focuses primarily on neurodevelopmental disorders, some evident in childhood, such as autism spectrum disorders, and others evident later, such as schizophrenia. It includes studies of causes at many levels, ranging from prenatal exposures to genetics/epigenetics to childhood sociocultural context; the potential for prevention; and ways of enhancing the quality of life of affected individuals over their life course. Much of Dr. Susser’s past research focused on the inter-relationships between sociocultural conditions and mental illness. This work included international studies (with WHO) of the incidence and course of psychotic disorders in differing contexts; studies of the relationships between mental illness and homelessness, as well as the broader contextual factors related to homelessness; and studies of the intersection of mental illness, homelessness and HIV infection. Extending to experimental studies, he developed the Critical Time Intervention (CTI) to prevent recurrence of homelessness among individuals with mental illness; this intervention proved successful in several studies and is now being adapted and tested in a variety of settings, including in Latin America.