Editing Psychopharmacology (section)

===Hypnotics===
[[Hypnotic]]s are often used to treat the symptoms of insomnia or other sleep disorders. Benzodiazepines are still among the most widely prescribed sedative-hypnotics in the United States today. Certain non-benzodiazepine drugs are used as hypnotics as well. Although they lack the chemical structure of the benzodiazepines, their sedative effect is similarly through action on the GABA<sub>A</sub> receptor. They also have a reputation of being less addictive than benzodiazepines. [[Melatonin]], a naturally-occurring hormone, is often used over the counter (OTC) to treat insomnia and jet lag. This hormone appears to be excreted by the pineal gland early during the sleep cycle and may contribute to human [[circadian rhythm]]s. Because OTC melatonin supplements are not subject to careful and consistent manufacturing, more specific melatonin agonists are sometimes preferred. They are used for their action on melatonin receptors in the [[suprachiasmatic nucleus]], responsible for sleep-wake cycles. Many barbiturates have or had an FDA-approved indication for use as sedative-hypnotics, but have become less widely used because of their limited safety margin in overdose, their potential for dependence, and the degree of [[central nervous system depression]] they induce. The amino-acid [[L-tryptophan]] is also available OTC, and seems to be free of dependence or abuse liability. However, it is not as powerful as the traditional hypnotics. Because of the possible role of serotonin in sleep patterns, a new generation of 5-HT<sub>2</sub> antagonists are in current development as hypnotics.<ref name=Clinical />