Which of the following is a depressant?

• A. Valium
• B. Cocaine
• C. Caffeine
• D. Ketamine

Answer: (A)

Depressants slow down brain activity and produce calming, sedating effects. Valium is a benzodiazepine, which enhances the brain’s inhibitory signals (GABA) to calm neural activity, relax muscles, and reduce anxiety—classic features of a depressant. Cocaine and caffeine are stimulants that ramp up CNS activity, increasing alertness and energy. Ketamine is a dissociative anesthetic with effects that differ from typical depressants; it can cause sedation and analgesia but isn’t classified as a conventional depressant like Valium. So Valium is the depressant.