Depression sufferers, in particular those who don’t respond to current antidepressants, may benefit from a new class of depression medication based on melatonin. A new European antidepressant which both binds to melatonin and blocks serotonin is proving to be an effective treatment for both depression and sleep disorders. Most people who suffer from depression also experience sleep disturbances.

Agomelatine is a melatonergic agonist and 5-HT2C antagonist developed by the French pharmaceutical company Servier. The new antidepressant medication both binds to receptors in the brain that control the circadian system (24 hour activity cycles), and blocks receptors for serotonin, a brain chemical known to have an effect on mood.

Agomelatine appears to have several advantages over current popular depression drugs.

It improves sleep quality, has reduced sexual side effects, and is easier to discontinue. In addition, it has been reported to be effective in as little as the first week. Three different studies indicated that the more depressed the patient is, the more effective agomelatine is. Another study found it significantly more effective than a placebo in the treatment of generalized anxiety disorder.

Agomelatine was approved in the European Union in 2009, under the brand names Melator, Valdoxan, and Thymanax. The multinational pharmaceutical giant Novartis purchased the rights to market the depression medication in the US in early 2006, and is currently undergoing phase III clinical trials in the hopes of seeking FDA approval in 2012.

Several studies have indicated that agomelatine is as effective as the commonly prescribed selective serotonin reuptake inhibitors (SSRIs) such as Lexapro, and selective serotonin norepinephrine reuptake inhibitors (SNRIs) such as Effexor and Effexor XR.

Melatonin is a hormone secreted by the pineal gland in the brain. It is known as the “hormone of darkness” as it is only produced in the dark. It affects the circadian rhythms of several biological processes, including the sleep-wake cycle. It is also a powerful antioxidant. Agomelatine was developed using melatonin as a model, and is very similar chemically.

Melatonin is available over the counter in the US. A prolonged release form on melatonin is sold in Europe and Israel as a prescription drug for insomnia.

Agomelatine is indicated for the treatment of major depressive disorder in adults, but there is limited research on its effectiveness in children and adolescents or the elderly.