Widespread use of psychoactive substances was a component of human behavior before the advent of civilization. In this course, we will examine the how and why of human drug use. We will focus on the biological mechanisms of drug action and how this in turn affects human behavior. We will also explore drug use/abuse from a societal perspective across different times and cultures. Taking a social justice perspective, we will examine how current drug laws affect society at-large, how the enforcement of certain drug laws affects under-represented groups, and whether/how anti-drug laws are effective at curbing drug abuse and its associated criminal behaviors.