A drug is anything ingested or absorbed, other than food, which affects the way a person's body or mind functions.
There are three main categories of drugs:
- Stimulants, which excite or speed up functions of the central nervous system (e.g., caffeine, cocaine, and ecstasy).
- Depressants, which slow down functions of the central nervous system (e.g., alcohol, marijuana, prescription pills).
- Hallucinogens, which affect the senses and changes awareness and perception (e.g., LSD, ecstasy, marijuana, salvia).