Madeline Meier is an associate professor in the Department of Psychology at Arizona State University. She received her PhD from the University of Missouri; completed her clinical internship at the Durham Veterans Affairs Medical Center; and completed her postdoctoral training at Duke University. Her research uses prospective longitudinal and case-control designs to understand the causes, course, and consequences of problematic substance use. She has published over 25 articles on cannabis use and the implications of long-term cannabis use for cognitive functioning, psychosocial functioning, mental health, and physical health. Her work has received extensive attention from both the scientific community and the media, and is being used by scientists, policy makers, and practitioners.