This document discusses depressants and their effects. It describes how depressants slow down the central nervous system and mental functions. Alcohol is the most commonly used depressant and can cause feelings of calm in low doses but loss of consciousness or death in high doses. Long term alcohol abuse can lead to health issues like liver disease and alcoholism. The document also outlines techniques for detecting ethanol in breath, blood, and urine samples and discusses the synergistic effects of mixing alcohol with other drugs. It identifies other commonly prescribed depressants like benzodiazepines, Valium, and Prozac.