Certified Addiction Counselor (CAC) Practice Exam 2026 - Free CAC Practice Questions and Study Guide

The primary function of CNS depressants is to slow basic physiological functions. These substances affect the central nervous system by enhancing the effects of a neurotransmitter called gamma-aminobutyric acid (GABA), which results in a calming effect on the brain and body. This slowing effect can lead to decreased heart rate, lowered blood pressure, and reduced respiration, among other physiological changes.

CNS depressants are often utilized in clinical settings to treat conditions such as anxiety, insomnia, and seizures, as they help to induce relaxation and sedation. Their primary action is to inhibit certain brain activities, thus potentially providing relief from hyperactivity or excessive stimulation.

In contrast, the other options describe functions that are not aligned with the characteristics of CNS depressants. Enhancing mood, stimulating the central nervous system, and improving motor coordination relate more closely to other classes of substances, such as stimulants or mood enhancers, rather than depressants. This understanding highlights why the correct choice focuses specifically on the depressant effect on physiological processes.