Four 10 to 15 minute sleep interruptions in the night enough to leave people groggy and grumpy.
A full night’s sleep which is interrupted can be as bad as getting only half a night, finds a new study taking a novel approach to sleep problems.
Despite how common it is for parents of young children to be awakened many times during the night, the effects have never been systematically investigated.
Parents are not the only ones who suffer, explains Prof. Avi Sadeh, who led the new research:
“Doctors on call, who may receive several phone calls a night, also experience disruptions.
These night wakings could be relatively short — only five to ten minutes — but they disrupt the natural sleep rhythm.
The impact of such night wakings on an individual’s daytime alertness, mood, and cognitive abilities had never been studied.
Our study is the first to demonstrate seriously deleterious cognitive and emotional effects.”
In their study participants were awakened four times during a normal 8-hour night (Kahn et al., 2014).
Each time they had to complete a computer task that took 10-15 minutes before they went back to bed.
In the morning they took tests of alertness, attention and mood. These were compared with results from two other nights when they’d had either:
- An uninterrupted 8 hours.
- An artificially restricted 4 hours.
The effects on mood, attention and alertness for the interrupted 8 hours were as drastic as only getting 4 hours sleep.
In comparison to the uninterrupted 8 hours, people felt more depressed, fatigued, confused and lower in vigour.
And this was the effect of just one interrupted night.
These deleterious effects can snowball, as Sadeh explained:
“Our study shows the impact of only one disrupted night.
But we know that these effects accumulate and therefore the functional price new parents — who awaken three to ten times a night for months on end — pay for common infant sleep disturbance is enormous.
Besides the physical effects of interrupted sleep, parents often develop feelings of anger toward their infants and then feel guilty about these negative feelings.”
Image credit: Simon Pais-Thomas
