Which drug increases the activity of the central nervous system?

Which drug increases the activity of the central nervous system?

• A. Marijuana
• B. Barbiturates
• C. Alcohol
• D. Cocaine

Answer: (D)

Cocaine acts as a stimulant, meaning it increases activity in the central nervous system. It does this mainly by blocking the reuptake of dopamine, norepinephrine, and serotonin in brain synapses, which floods these neurotransmitters into the gaps between neurons. That surge heightens arousal, energy, alertness, and often euphoria, and it also ramps up sympathetic nervous system activity (faster heart rate, higher blood pressure, dilated pupils). The other substances here are not primarily stimulants. Barbiturates and alcohol are CNS depressants, slowing brain activity and producing sedation and intoxication. Marijuana has a mixed profile but is not primarily a CNS stimulant and tends to alter perception and mood rather than markedly boosting overall CNS arousal. Thus cocaine best fits the description of increasing CNS activity.

Cocaine acts as a stimulant, meaning it increases activity in the central nervous system. It does this mainly by blocking the reuptake of dopamine, norepinephrine, and serotonin in brain synapses, which floods these neurotransmitters into the gaps between neurons. That surge heightens arousal, energy, alertness, and often euphoria, and it also ramps up sympathetic nervous system activity (faster heart rate, higher blood pressure, dilated pupils).

The other substances here are not primarily stimulants. Barbiturates and alcohol are CNS depressants, slowing brain activity and producing sedation and intoxication. Marijuana has a mixed profile but is not primarily a CNS stimulant and tends to alter perception and mood rather than markedly boosting overall CNS arousal. Thus cocaine best fits the description of increasing CNS activity.