Difference between depressant stimulant and hallucinogen?

Stimulants: Drugs that speed up or excite the central nervous system and make you feel more alert, more energetic, help you stay awake for long periods of time, decrease your appetite and make you feel good. (ex. relaxed, euphoric) Examples: Caffeine, Tobacco, Cocaine Depressants: Drugs that slow down the functions of the central nervous system and make you less aware of the events around you. Examples: Alchohol, Opiales (Heroin) Hallucinogens: (Psycadelics) Drugs that distort the senses and one's awareness or perception of events. One might see or hear things that don't actually exist. Examples: Magic Mushrooms