Impairment Tests Show Impact Sleep-Onset Insomnia

Devon A. Hansen, PhD

While the benefits of sleep are well-known, new data shows how sleep deprivation impacts cognitive scores for those suffering from sleep-onset insomnia.

A team of investigators, led Devon A. Hansen, PhD, Sleep and Performance Research Center, Washington State University, used a laboratory-based total sleep deprivation (TSD) paradigm to decipher psychomotor vigilance performance in patients with chronic sleep-onset insomnia.

The study included 14 participants, half of which suffer from chronic sleep-onset insomnia and 7 healthy controls. The age range of the patients was 24-40.

Each patient completed a highly controlled in-laboratory involving 38 hours of total sleep deprivation.

A 10-minute and 3-minute version of the psychomotor vigilance test was administered every 3 hours during total sleep deprivation.

In both the individuals with sleep-onset insomnia and the age-matched normal sleepers, lapses of attention and false starts on the psychomotor vigilance test (PVT) were relatively infrequent during the first 16 hours of the total sleep deprivation period. However, they became frequent when wakefulness was extended beyond 16 hours.

The effects of total sleep deprivation period on the psychomotor vigilance test performance was considerably exacerbated in the sleep-onset insomnia group, which showed about twice as many lapses of attention, more than twice as many false starts, and approximately twice as big a time-on-task effect on the 10-minute PVT as the control group.

There were similar findings on the 3-minute PVT.

People with primary insomnia often suffer from cognitive impairment as a next-day consequence of disrupted sleep.

However, past studies seeking to quantify daytime impairment objectively in people with insomnia have yielded mixed results, with evidence suggesting impairments in aspects of executive functioning and not psychomotor vigilance.

Researchers have suggested that individuals with insomnia could have latent performance deficits where they would be able to compensate effectively under normal daytime circumstances. If true, this would suggest that any deficits may be exposed through perturbation.

“These findings indicate that daytime impairment reported by individuals with sleep-onset insomnia has an objective performance component that is exposed during TSD,” the authors wrote. “Thus, persons with sleep-onset insomnia could be at increased risk of performance impairment in settings that involve extended wakefulness.”

The results ultimately underscore the importance of treating insomnia, suggesting that laboratory sleep deprivation studies could serve to document the effectiveness of treatment approaches.

Earlier this year, investigators presented data from a new poll during the 2019 World Sleep Congress in Vancouver showing how the impact of sleep and rest impacts next day performance.

The poll, sponsored by Elsai Inc., included 525 adults in the US who have been diagnosed with insomnia or have experienced difficulties falling asleep or staying asleep for 3 or more nights a week, over a 3-month period.

The survey also included 505 adults in the US who did not have sleep problems, but resided with an adult diagnosed with insomnia or experience difficulties falling or staying asleep for 3 or more nights a week, over a 3-month period.

The pharmaceutical company discovered that 90% of patients agreed that “having a good night’s sleep” equates with “having a good day” the subsequent morning.

They found that 67% of those surveyed reported feeling of fatigue following a poor-quality sleep, while just 7% reported feeling “ready to start their day.”

Also, 63% of the participants rated “waking up refreshed and ready to start the day” and 64% of those surveyed said “being able to function normally throughout the day” were very important in managing insomnia and other sleep difficulties.

The study, “Psychomotor Vigilance Impairment During Total Sleep Deprivation Is Exacerbated in Sleep-Onset Insomnia,” was published online in Nature and Science of Sleep.