Although risk of substance use disorder exists for anyone that uses substances, study after study shows that early initiation of substance use in adolescence is a strong predictor of later substance-related problems and is associated with higher risk . What is going on in the brain during adolescence, and how do substances affect it? Dr. Lindsay Squeglia discusses the development of the brain during adolescence and the risks of substance use during adolescence, and attempts to answer our questions about the chicken or the egg. Dr. Squeglia also talks about her efforts to create evidence-based psychoeducation programs about substance use for adolescents and programs to help teens get involved in science. Dr. Lindsay Squeglia is a Professor of psychiatry and behavioral sciences in the College of Medicine at the Medical University of South Carolina, and a Co-Director of the MUSC Youth Collaborative. Find out more about her work here.