National Certified Addiction Counselor, Level I (NCAC I) Practice Exam 2026 – Comprehensive All-in-One Guide to Exam Success!

The substance commonly classified as a CNS depressant is alcohol. Central Nervous System (CNS) depressants are drugs that slow down brain activity, leading to a calming effect on the mind and body. Alcohol acts on the brain by enhancing the effects of the neurotransmitter gamma-aminobutyric acid (GABA), which leads to sedation, relaxation, and in some cases, drowsiness. This makes alcohol distinct from stimulants, which increase brain activity.

In contrast, substances like caffeine and nicotine are stimulants that increase heart rate and alertness, while cocaine stimulates the CNS by increasing dopamine levels, leading to euphoric effects, heightened energy, and increased alertness. Understanding the classifications of substances is crucial in addiction counseling, as it helps in identifying and treating substance use disorders effectively.