Which term best describes drugs such as alcohol, benzodiazepines and barbiturates?

• A. Depressants/Sedative-hypnotics
• B. Stimulants
• C. Hallucinogens/Dissociatives
• D. Cannabinoids/cannabinols

Answer: (A)

The main idea is that these substances are central nervous system depressants, also called sedative-hypnotics. Their primary effect is to slow brain activity, which leads to relaxation, reduced anxiety, drowsiness, and, at higher doses, sleep or unconsciousness. Alcohol, benzodiazepines, and barbiturates all depress neural activity, though they do so via different mechanisms (for example, they enhance inhibitory signaling in the brain, especially through GABA receptors). This slowing of CNS activity is what sets them apart from other classes.

Stimulants, by contrast, increase brain activity and arousal; hallucinogens/dissociatives mainly alter perception and cognition rather than simply slowing activity; cannabinoids/cannabinols produce a mix of mood and perceptual effects but are not primarily categorized as depressants.