Addiction is a complex disease. It affects the functioning of the brain and body. People abuse substances like drugs and alcohol for varied reasons. They engage in behaviors that become compulsive and often continue despite harmful consequences. How does harmful substance use and addictive behaviors damage the brain? Dr. Ruth Potee, Medical Director for Addiction Services at Behavioral Health Network, is an expert in the field of addiction. Potee sits down with Ray Hershel to discuss the physiology of addiction, including what drug use does to the brains and why people become addicts.