Summary: A study found that people with insomnia disorder often have intact sleep-wake perception systems, suggesting their symptoms stem more from persistent cognitive, emotional, and behavioral patterns than from actual misperception of sleep or structural sleep issues.
Key takeaways:
- Insomnia symptoms are likely driven by sustained cognitive, emotional, and behavioral mechanisms rather than sleep-wake misperception or structural brain issues.
- The findings reinforce CBT-I as a first-line treatment over pharmacological approaches.
- The study supports a shift toward understanding insomnia within a sleep-wake continuum and tailoring interventions accordingly.
People with insomnia disorder present with subjective complaints of reduced quantity or quality of sleep that often don’t correspond to objective sleep measurements. Does that mean their direct sleep-wake perception regulatory systems have gone awry? No, finds a new study by Geneva University Hospitals, the University of Geneva, and the Universitäre Psychiatrische Dienste Bern at the University of Bern.
Surprisingly, sleep-wake perception regulatory systems are often intact in patients with insomnia disorder, according to the study of 60 people (30 with insomnia and 30 controls). The authors, led by PhD student Carlotta Schneider, say their finding highlights the opportunity to contribute to improvements of sleep-related complaints through cognitive behavioral therapy for insomnia (CBT-I), rather than medication-based treatment.
After two nights dedicated to adaptation and sleep data collection, on a subsequent experimental night, participants in both groups were awakened up to 12 times during non-rapid eye movement (NREM) sleep via a vibrating bracelet and asked about their perception of having been asleep or awake through an automated interview.
In approximately half of the awakenings, participants in both groups reported that they had been asleep, whereas in the other half, they stated that they had been awake. High-frequency brain activity during sleep, considered an index of arousal, was associated with the perception of having been awake across groups. Although patients reported substantial subjective complaints about their sleep, objective sleep parameters and direct sleep-wake perception did not significantly differ from those of healthy participants.
These findings suggest that the perception of wakefulness from NREM sleep is frequent, physiological, and not limited to patients with insomnia disorder. However, the protocol did not wake patients up from REM sleep—so it can’t contribute to the REM sleep instability hypothesis. “We believe that characterizing REM sleep is of great interest and see NREM sleep studies as complementary towards a more comprehensive understanding of the complex perception of sleep and the pathophysiology of insomnia disorder,” the authors say in the paper.
So what is causing the symptoms of insomnia then, if it’s not structural brain alterations, sleep loss, or even direct sleep-wake misperceptions? The authors suspect it’s via:
- sustained cognitive mechanisms (like rumination, catastrophizing, generalization),
- sustained emotional mechanisms (like anxiety), and
- sustained behavioral mechanisms (like extended bedtimes).
“The negative evaluation of sleep appears to arise over time with worries and anxiety towards sleep,” they say.
These results have potential implications for concepts of insomnia disorder and sleep-wake regulation, as well as future treatment developments. They support the notion that many patients, after exclusion of specific organic sleep or other disorders, can learn to improve their sleep-related difficulties through CBT-I. Further studies are currently underway on the concept of a sleep-wake continuum, potential subgroups of patients, and broader implementation of CBT-I.
