Which of the following is not listed as causing drowsiness?

Which of the following is not listed as causing drowsiness?

• A. Narcotics
• B. Depressants
• C. Antihistamines
• D. Stimulants

Answer: (D)

Drowsiness comes from substances that slow brain activity. Narcotics slow CNS function, producing sleepiness and reduced alertness. Depressants like alcohol and many sedatives also dampen brain activity, leading to drowsiness. Antihistamines, especially older ones, block histamine signals in the brain that help keep you awake, resulting in sedation. In contrast, stimulants increase CNS activity and promote wakefulness, so they do not cause drowsiness. That’s why the option that does not cause drowsiness is stimulants. (Note: stimulants can cause other effects like insomnia or jitters, but they don’t typically induce sleepiness.)

Drowsiness comes from substances that slow brain activity. Narcotics slow CNS function, producing sleepiness and reduced alertness. Depressants like alcohol and many sedatives also dampen brain activity, leading to drowsiness. Antihistamines, especially older ones, block histamine signals in the brain that help keep you awake, resulting in sedation. In contrast, stimulants increase CNS activity and promote wakefulness, so they do not cause drowsiness. That’s why the option that does not cause drowsiness is stimulants. (Note: stimulants can cause other effects like insomnia or jitters, but they don’t typically induce sleepiness.)