The document discusses drug addiction. It defines different types of drugs like stimulants, depressants, and hallucinogens. It explains that addiction has causes like exposure to drugs from peers, poor home life, parent usage, psychological issues, availability, genetics, and peer pressure. The document shows how drugs affect the brain by including images that compare normal, healthy brains to brains that have been impacted by long term usage of drugs like heroin, cocaine, meth, marijuana, and alcohol.