Which of the following is an example of a stimulant?

• A. Cocaine
• B. Diazepam
• C. Lidocaine
• D. Peppermint oil

Answer: (A)

Stimulants are substances that raise the activity of the central nervous system, boosting alertness, energy, and physiological arousal by increasing monoamine signaling in the brain. Cocaine fits this description best because it blocks the reuptake of dopamine, norepinephrine, and serotonin, causing a surge of these neurotransmitters in synapses. That rise drives heightened energy, focus, and a feeling of euphoria, although it comes with significant risks like addiction and heart problems.

Diazepam is a depressant; it enhances GABA activity, which calms the nervous system and reduces arousal. Lidocaine is a local anesthetic that blocks sodium channels to prevent nerve signaling, not increasing CNS activity. Peppermint oil may produce a momentary sensory alertness via aroma, but it isn’t classified as a central stimulant drug like cocaine.