Slide 1: The National Institute on Drug Abuse (NIDA) is part of the National Institutes of Health and dedicated to bringing the power of science to bear on drug abuse and addiction.

When a person first thinks about trying drugs, it is usually a voluntary decision. “Maybe I should see what it’s like... just this once,” you might think. Or a friend dares you. Or you just want to feel good or forget your troubles. Most drugs of abuse - including nicotine, alcohol, marijuana, cocaine, and heroin - activate a part of the brain called the reward system, and that makes you feel good. But just for a little while.
 
Drug abuse has serious consequences. The most serious consequence is that prolonged drug use changes the brain in fundamental and long-lasting ways. Eventually, it becomes difficult to experience other pleasures.
After repeated drug use, you reach a point when deciding to use drugs is no longer voluntary. Scientists have proof now that drugs literally change your brain. It’s as if a “switch” goes off in the brain. At that point, the drug abuser becomes a drug addict.

Addiction is actually a different state of being - a brain disease. Addiction is a chronic relapsing disease characterized by compulsive, often uncontrollable, drug seeking and drug use in the face of negative consequences. Drug addicts need professional help and treatment to help them cope with these changes and possibly change the brain back to normal.