 Melatonin in the form of prolonged release (trade name Circadin®) was approved in 2007 in Europe (EU) for use as a short-term treatment, in patients 55 years or older, for primary insomnia (poor quality of sleep).Products containing melatonin are available as a dietary supplement in the United States and Canada.In 2009 agomelatine (Valdoxan®, Melitor®, Thymanax®) was also approved in Europe and is indicated for the treatment of major depressive disorder in adults.