Drugs are broadly divided into three categories: stimulants, depressants and hallucinogens.
Stimulants make you feel alert and boost your confidence. They include cocaine, speed, ecstasy, and mephedrone.
Depressants make you feel relaxed and chilled out. They include alcohol, tranquillisers, heroin and cannabis.
Hallucinogens can alter our sense of reality and movement. They include LSD and magic mushrooms.
Some drugs fit into more than one of these categories and can have mixed effects.