A depressant is defined as...

• A. A type of drug that slows down the central nervous system.
• B. A drug that speeds up brain activity.
• C. A drug that allays pain without affecting CNS.
• D. A drug that improves memory.

Answer: (A)

Depressants slow the central nervous system. By reducing brain activity, they calm you, make you sleepy, and slow reflexes and movements. That’s why this option is correct: it describes a drug that slows the CNS. It’s different from stimulants, which speed up brain activity. The idea of a drug that doesn’t affect the CNS or of memory-boosting drugs doesn’t fit the defining feature of depressants, since these substances typically impair memory and concentration rather than improve them.