A study sheds surprising light on insomnia, a widespread sleep disorder affecting between 5 and 10% of adults. Despite the frequent feeling of disrupted sleep among these individuals, it appears that sleep regulation mechanisms generally remain functional.
In this study, conducted by Carlotta Schneider under the supervision of Professor Christoph Nissen, researchers compared 30 healthy individuals with 30 insomnia patients. The experiment involved deliberately waking participants during their deep sleep using a vibrating bracelet, then immediately asking them whether they had been asleep or awake at the moment of awakening.
Surprisingly, responses were similar in both groups. About half of the participants thought they were asleep, while the other half felt awake. Brain activity measurements showed a general correspondence between participants' perceptions and their actual brain state: those who felt awake often had brain activity close to wakefulness, despite having previously been recorded in deep sleep. This result was similar for both insomniacs and healthy individuals.
Sleep or wakefulness: a blurred boundary
This finding supports the idea that the boundary between sleep and wakefulness is more flexible than previously thought. In reality, our brains seem to constantly oscillate between these two states, even during deep sleep phases. This phenomenon, called the "sleep-wake continuum," partly explains why some insomniacs perceive their sleep as insufficient or disrupted, even when their sleep cycles remain normal.
The results, published in the journal
Scientific Reports, show that cognitive behavioral therapy for insomnia (CBT-I) could be particularly beneficial, even preferable to medication.
These findings suggest that insomnia-related difficulties might be amplified by psychological, emotional, or behavioral mechanisms accumulated over time. Rather than directly resorting to medication, which is often associated with risks of side effects or dependency, CBT-I therefore represents an effective approach to help patients better manage their sleep.
This research, conducted by scientists from the Geneva University Hospitals (HUG), the University of Geneva (UNIGE), and the University of Bern (UniBE), also opens the door to new studies on the concept of the sleep-wake continuum and the best ways to treat insomnia without medication.