Which of the following classes of drugs does NOT typically depress the central nervous system?

The class of drugs that does not typically depress the central nervous system is cocaine. Cocaine functions primarily as a stimulant, rather than a depressant. It increases alertness, heart rate, and energy levels, leading to an elevated state of arousal in the user. Cocaine achieves these effects through its action on neurotransmitters, particularly dopamine, by inhibiting its reuptake, which enhances its presence in the synaptic cleft and produces feelings of euphoria.

In contrast, anti-anxiety tranquilizers, barbiturates, and non-barbiturates are known for their central nervous system depressant effects. Anti-anxiety tranquilizers, such as benzodiazepines, are designed to reduce anxiety by dampening brain activity. Barbiturates, historically used for sedation, also depress CNS activity, leading to relaxation and decreased inhibition. Non-barbiturates, while structurally different from barbiturates, also share depressant effects on the CNS. Each of these categories is characterized by their ability to calm, sedate, or relax the user, which distinctly contrasts with the stimulant nature of cocaine.