Which substance is classified as a depressant?

Alcohol is classified as a depressant because it has a sedative effect on the central nervous system. This means that it slows down brain function and bodily processes, leading to decreased inhibitions, slow reaction times, and an overall calming effect. Depressants are substances that can induce relaxation and drowsiness, which are characteristic effects of alcohol consumption.

In contrast, the other choices listed are classified differently. Caffeine is a stimulant that increases alertness and energy levels. Amphetamines are also stimulants that can enhance mood and increase energy and focus. Cocaine is a powerful stimulant that elevates mood and energy and can create feelings of euphoria. Therefore, when considering the classification of these substances based on their effects on the central nervous system, alcohol distinctively fits the category of depressants.