Barbiturates are derived from barbituric acid, an alkaloid with nitrogen-containing rings. Belonging to a class of mood-altering drugs, barbiturates induce relaxation and sleep. By manipulating the central nervous system, barbiturates can effect degrees of behavioral depression from mild sedation to coma, and, if used improperly, can cause death. Barbiturates depress the activity of nerves, muscles, heart tissue, and the brain. They can impair a person's ability to engage in rational thought, thus diminishing their reasoning capacity.

The use of depressants likely began with alcohol consumption. Alcohol was once used as a remedy or anesthetic for practically all diseases and problems; in the Middle Ages, alcohol was viewed as a life-giving elixir. Many barbiturates have been prescribed to treat problems for which alcohol was once administered.

The first barbituric acid was prepared in 1864 by Adolf von Baeyer, but it was not until 1903 that his student, Emil Fischer, introduced the...