Exploring new frontiers for the pharmacological treatment of insomnia

Insomnia is the most common sleep disorder and approximately 10% of the world’s population will report that they suffer from chronic or persistent insomnia [1]. Insomnia is a condition of unsatisfactory sleep, either in terms of sleep onset, sleep maintenance or early waking. Furthermore, insomnia impairs daytime well-being and subjective abilities and functioning. Insomnia must be considered a ‘24-hour’ disorder [2]. In contrast with DSM-IV, the new Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-V) does not distinguish between primary insomnia and secondary insomnia. DSM-V recognizes that co-existing medical or mental conditions with sleep disorders (comorbid insomnia) are interactive and bidirectional. For this reason, the diagnosis of primary insomnia has been renamed insomnia disorder [3]. This change in the definition of insomnia will most likely change the approach to insomnia drug development