By Dawn Van Osdell
It’s no surprise to parents of newborns or kids with sleep challenges that waking several times throughout the night can really put you in a foul mood. A study just released from Johns Hopkins Medicine proves that your bad mood is more likely due to lack of quality sleep, than the reduced quantity of sleep you get. To feel better, you’re better off getting the same shortened amount of sleep without interruption.
“When your sleep is disrupted throughout the night, you don’t have the opportunity to progress through the sleep stages to get the amount of slow-wave sleep that is key to the feeling of restoration,” says the lead author of the study, Patrick Finan, Ph.D., an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.
The study, reported in the journal Sleep, evaluated 62 healthy men and women who in a research setting were assigned to three consecutive nights of either forced awakenings, delayed bedtimes, or uninterrupted sleep. Researchers monitored the subjects’ sleep stages using polysomnography, a test that records brain waves, blood oxygen levels, breathing, heart rate and movements during sleep. At the end of each night, participants were asked to report how strongly they felt positive or negative emotions, such as anger or cheerfulness.
The study found that after the second night, those who were awakened several times during the night reported a 31 percent reduction in positive mood. The delayed bedtime group showed a 12 percent decline. It also found that the interrupted sleep group experienced shorter periods of deep sleep—the sleep stage that is important for the body to repair itself and maintain health— and that disturbed sleep impacted certain aspects of their mood, including energy level, friendliness, and feelings of sympathy.
The effects of interrupted sleep on positive mood can be cumulative, the study also showed, which helps to explain why depression is often a symptom reported by those suffering from insomnia or chronic sleeplessness. “You can imagine the hard time people with chronic sleep disorders have after repeatedly not reaching deep sleep,” Finan says. It can be a real downer. And the same holds true for parents who wake repeatedly throughout the night to feed or soothe an infant or child.
Further studies are needed to learn how long it takes us to recover or make up for lost sleep. For now, we know it’s more important to get our kids to sleep through the night—so we can, too—than it is for us to turn in early.
Photo by Sander Smeekes via Unsplash