Long-Term Efficacy of Ramelteon on Endocrine Function in Adult Subjects With Chronic Insomnia

Insomnia is characterized by a complaint of either difficulties initiating and maintaining sleep or of nonrestorative and non-refreshing sleep. Transient insomnia affects approximately one-third to one-half of the US population, based on the results of 2 surveys of representative samples of the adult US population conducted by the Gallup Organization in which respondents were asked if they had "ever had difficulty sleeping." Based on reports of "regular" or "frequent" sleep difficulty, results from the same studies suggest that approximately one-tenth of the US population experiences chronic insomnia. The ideal treatment for insomnia would reduce the latency to onset of sleep and increase total sleep time, without a negative impact on sleep architecture and without safety concerns or next-day effects. Ramelteon is a melatonin-1 receptor agonist under global development by Takeda Chemical Industries, Ltd., Osaka, Japan, for the treatment of transient and chronic insomnia and for the treatment of Circadian Rhythm Sleep Disorders. This study has been designed to determine the long-term (6 month) effects of Ramelteon on endocrine function values. Study participation is anticipated to be about 7 months.