Which of the following is a depressant?

Which of the following is a depressant?

• A. Alcohol
• B. Benzedrine
• C. Barbiturates
• D. Caffeine

Answer: (C)

Depressants slow brain activity. Barbiturates are a classic CNS depressant class that work by enhancing GABA signaling at GABA-A receptors, which increases chloride ion influx into neurons. This makes neurons less excitable, producing calming effects, sleep, and at higher doses anesthesia. They’ve been used as sedatives, sleep aids, and anticonvulsants, with examples like phenobarbital and secobarbital. The other options are stimulants (Benzedrine and caffeine), which raise CNS activity. Alcohol also depresses the CNS, but barbiturates are a prototypical and well-recognized depressant in this context.

Depressants slow brain activity. Barbiturates are a classic CNS depressant class that work by enhancing GABA signaling at GABA-A receptors, which increases chloride ion influx into neurons. This makes neurons less excitable, producing calming effects, sleep, and at higher doses anesthesia. They’ve been used as sedatives, sleep aids, and anticonvulsants, with examples like phenobarbital and secobarbital. The other options are stimulants (Benzedrine and caffeine), which raise CNS activity. Alcohol also depresses the CNS, but barbiturates are a prototypical and well-recognized depressant in this context.