Which of the following is considered a depressant?

The correct answer is alcohol, which is classified as a depressant because it slows down the central nervous system. Depressants reduce anxiety, induce relaxation, and lower inhibitions by affecting neurotransmitters in the brain, particularly gamma-aminobutyric acid (GABA). When consumed, alcohol can lead to sedative effects and impair cognitive functions and motor skills.

In contrast, marijuana is often considered a psychoactive substance that can have varying effects, including relaxation and euphoria, but it does not strictly fit within the depressant category as its effects can be classified more broadly. Cocaine is a stimulant, which means it actually speeds up the brain's activity and increases alertness and energy. LSD, or lysergic acid diethylamide, is a hallucinogen that alters perception and has psychedelic effects rather than depressant ones. Understanding these classifications helps clarify the distinct effects and implications of each substance.