Does late morning waking-up affect sleep during the following night in patients with primary insomnia?

Abstract

Night-to-night variability in sleep duration and schedule is common in patients with insomnia. Among the various sleep variables, waking-up time is focused upon as the important factor for cognitive behavioural therapy for insomnia. This study examined the effect of a single late waking-up episode on sleep in the immediate following night in patients with chronic insomnia, using data from a placebo group (380 patients) of a double-blind placebo-controlled study. Patients tended to wake up later and have a longer total sleep time on weekends than weekdays. It was suggested that patients who woke up late one morning ( later than the individual’s regular waking-up time) extended their sleep onset latency by 4.3 min in the immediate following night. The effects of late waking-up on total sleep time and bedtime were not clear. The importance of keeping regular waking-up time is highlighted for better sleep in patients with insomnia.

Keywords:

• insomnia
• sleep onset latency
• waking-up time
• weekend
• irregular sleep

Acknowledgements

We wish to thank Takeda Pharmaceutical Company Limited for their generosity in allowing us to access their placebo data. We sincerely thank Dr Shiro Tanaka of Kyoto University for his valuable suggestions and comments on our manuscript. The study was in part supported by research grant from the Kanae Foundation for the Promotion of Medical Science.