Which of the following is a stimulant?

Which of the following is a stimulant?

• A. LSD
• B. Cannabis
• C. Caffeine
• D. Cocaine

Answer: (D)

Stimulants are drugs that raise CNS activity, increasing wakefulness, energy, and sympathetic arousal. Cocaine fits this profile strongly because it blocks the reuptake of dopamine, norepinephrine, and serotonin in brain synapses. This reuptake block floods these neurotransmitters in the synaptic space, producing rapid, heightened alertness, euphoria, increased energy, and often a fast heart rate and dilated pupils. LSD, on the other hand, is a hallucinogen that mainly alters perception through serotonin receptors, not by broadly boosting CNS arousal. Cannabis has complex psychoactive effects that can include relaxation or mood changes rather than pure stimulation. Caffeine is a stimulant as well, via adenosine receptor blockade, but among these options cocaine represents the strongest and most classic example of a stimulant in terms of both mechanism and intensity.

Stimulants are drugs that raise CNS activity, increasing wakefulness, energy, and sympathetic arousal. Cocaine fits this profile strongly because it blocks the reuptake of dopamine, norepinephrine, and serotonin in brain synapses. This reuptake block floods these neurotransmitters in the synaptic space, producing rapid, heightened alertness, euphoria, increased energy, and often a fast heart rate and dilated pupils. LSD, on the other hand, is a hallucinogen that mainly alters perception through serotonin receptors, not by broadly boosting CNS arousal. Cannabis has complex psychoactive effects that can include relaxation or mood changes rather than pure stimulation. Caffeine is a stimulant as well, via adenosine receptor blockade, but among these options cocaine represents the strongest and most classic example of a stimulant in terms of both mechanism and intensity.