Which of the following is considered a depressant?

Alcohol is classified as a depressant because it acts primarily on the central nervous system to reduce neuronal activity. This leads to a range of effects, including sedation, relaxation, and a decrease in inhibitions. Depressants generally lower brain function, which can result in drowsiness and impaired coordination, making tasks that require concentration much more difficult.

In contrast, the other substances listed—caffeine, nicotine, and cocaine—are stimulants. Caffeine increases alertness and energy levels, nicotine stimulates the release of neurotransmitters that can heighten attention and boost mood, while cocaine significantly boosts energy and euphoria by increasing dopamine levels in the brain. Understanding these classifications is important in the field of substance abuse, as they help inform treatment and management strategies for substance use disorders.