What class of drugs is known to depress the activity of the central nervous system?

Barbiturates are a class of drugs specifically designed to depress the activity of the central nervous system (CNS). They act by enhancing the effect of the neurotransmitter gamma-aminobutyric acid (GABA), which results in sedative and anxiolytic effects. This can lead to a decrease in anxiety, relaxation, and sedation, making barbiturates effective for treating conditions such as insomnia and anxiety disorders, albeit with risks of addiction and overdose.

In contrast, antidepressants primarily aim to elevate mood and improve symptoms of depression, rather than depress the CNS. Stimulants, as the name suggests, increase CNS activity, enhancing alertness and energy levels. Hallucinogens alter perception and can lead to distorted sensory experiences, but they do not primarily function by depressing CNS activity. Therefore, barbiturates are uniquely known for their depressant effects on the central nervous system.