Chronic insomnia is a prevalent (10%) medical disorder defined by difficulty falling or staying
asleep or non-restorative sleep combined with impaired daytime functioning [1]. It is associated with
increased motor vehicle accidents, and falls [2], increased healthcare utilization [3], and decreased
survival rates [4]. Insomnia predisposes to the development of a number of psychiatric disorders,
particularly depressive and anxiety disorders [5,6]. When psychiatric disorders are present, insomnia
is associated with greater severity of illness including suicidal behavior [7–9]. Successful treatment of
insomnia frequently leads to an earlier antidepressant and anxiolytic response [10,11]. Insomnia also
interacts with various medical conditions; it can predispose to the development of type 2 diabetes,
metabolic syndrome, and obesity [12]. In addition, treatment of insomnia co-morbid with a medical
illness may lead to improvement of both conditions [13]. Thus, there is a clear need to treat insomnia.