Many commonly known depressants are Alcohol, Barbiturates, Benzodiazepines, and Gamma Hydroxybutyric Acid (GHC). Depressants are substances that inhibit the normal function of the central nervous system. Depressants are often abused and addictive. These drugs slow down the central nervous system, increasing the symptoms and likelihood of drowsiness, inhibition, coma and sometimes death. Depressants are endogenous compounds that act as sedatives and slow down normal brain function.