Sedatives are drugs or medications that act as depressants and slow down functioning of the central nervous system. Most sedatives affect the neurotransmitter Gamma-aminobutyric acid (GABA) which decreases activity in the brain. Sedatives have a relaxing effect which is used to treat anxiety and sleep disorders. Common sedatives include barbiturates and benzodiazepines. Sedatives do have a risk of being abused so they should be used only when needed. Withdrawal symptoms can occur if an individual becomes addicted and usage stops. Sedatives can cause death at high doses or if used in conjunction with other CNS depressants.