Which of the following substances is NOT listed as a CNS depressant?

Cocaine is the correct answer because it is classified as a central nervous system (CNS) stimulant rather than a depressant. CNS stimulants increase brain activity, leading to heightened alertness, increased energy, and potentially increased heart rate and blood pressure. This is in stark contrast to CNS depressants, which slow down brain function and are often associated with effects such as sedation, decreased anxiety, and muscle relaxation.

Chloral hydrate, meprobamate, and Quaaludes (which are a brand name for methaqualone) are all known to be CNS depressants. These substances are commonly used for their sedative and anxiolytic properties, making them effective in the treatment of insomnia and anxiety but also carrying a risk of dependence and overdose. Thus, recognizing cocaine as a stimulant and not a depressant is critical in understanding the pharmacological classifications of substances.