Thad Leffingwell

Thad Leffingwell is a Professor in the Department of Psychology at Oklahoma State University, where he also serves as an Assistant Dean in the College of Arts and Sciences. He directs the THAD Laboratory (Tobacco, Health and Drinking), conducting innovative clinical health research focused on understanding when, why, and how people make health behavior changes, particularly regarding high-risk habits like smoking, binge drinking, and drug use.

Dr. Leffingwell completed his Ph.D. in Psychology at the University of Washington and completed his pre-doctoral internship at the Puget Sound VA Healthcare System in Seattle. His academic progression at Oklahoma State University shows advancement from Assistant Professor (2000-2007) to Associate Professor (2007-2013) to his current position as Professor (2013-present).

His research is theoretically informed by transtheoretical models, social learning models, and self-determination models of behavior change, with clinical applications rooted in motivational enhancement and personalized feedback approaches. A member of the Motivational Interviewing Network of Trainers (MINT), he has worked on numerous federal, state, and privately funded intervention projects. His work often focuses on developing technology-based interventions that can be widely disseminated to improve public health outcomes.

Analysis of his recent publications (2020-2024) reveals a strong focus on substance use among college populations, with particular attention to vulnerable groups including American Indian/Alaska Native communities. His research spans assessment development, intervention efficacy testing, and exploration of underlying psychological mechanisms driving health behaviors.

Dr. Leffingwell maintains an active research team with multiple doctoral students (Hannah Appleseth, Grace Walker, Emily Warner), undergraduate assistants, and has successfully mentored numerous Ph.D. graduates over his career. His research has been featured in media outlets including The O'Colly, EurekAlert!, The Oklahoman, and BBC, demonstrating the public impact of his work.

The THAD Laboratory has produced significant research on brief interventions for college alcohol misuse, electronic interventions, and studies examining the effects of campus policies on substance use behaviors. His work integrates both traditional clinical approaches and innovative technological solutions to address complex health behavior challenges.