Sleep Deprivation Has a Two-Way Effect on Anxiety, Study Suggests
"Anxiety and sleep loss are very very closely linked..."
The crushing weight of anxiety can make sleep difficult. But mounting research suggests that we ought look at things from the opposite point of view: Enough sleep will make feeling anxious less likely.
A recent study that speaks to the strong connection between sleep loss and anxiety recently debuted — the paper is forthcoming — at the Society For Neuroscience’s 2018 Conference in San Diego. Here, a team from UC Berkeley’s Center for Human Sleep Science conducted an experiment to test the hypothesis that sleep loss might be responsible for high levels of anxiety in healthy people. For instance, study author and postdoctoral researcher Eti Ben-Simon, Ph.D., tells Inverse that after a night of disturbed sleep, nearly 50 percent of her healthy participants showed anxiety scores that were on par with the scores of those who struggle with clinical anxiety.
“I think that it’s important to keep in mind that anxiety and sleep loss are very, very closely linked across both heathy populations and clinical populations,” she says. “I think it highlights the potential of intervening through sleep.”
Ben-Simon showed this link through examining outward signs of anxiety in her participants by having them undergo nights of very different types of sleep: one full night of rest and an all-nighter (24 hours of sleep deprivation). In each condition the participants took a test designed to measure anxiety levels before they began the night, and then once again the next morning. That’s where she saw the gap in anxiety scores, which are strong though not exactly unprecedented. But this study goes a bit deeper to propose why we may feel this way, using neuroimaging to illustrate whether these behavioral differences were backed by a pattern of change in the brain.
Here, she confronted her participants with an emotional stimulus intended to elicit a response. In this case, a video showing pictures of disturbing things, like human suffering or animal abuse. She explains that they did this to track how their subjects brains dealt with these disturbing images when they were operating on limited sleep.
“We focused on regions that we know are altered in people with anxiety disorders,” she explains. “What we found is that after sleep deprivation we’re getting an image similar to what we see in people with anxiety disorder,” she says.
When her sleep-deprived subjects watched those videos, she found that areas of the brain involved in emotional processing were not just active, but they seemed to be overactive — particularly the amygdala and the dorsal anterior cingulate tended to show higher activity than when participants who’d slept through the night saw the same footage. Importantly, she also found that area dedicated to regulating those feelings of anxiousness, namely the medial prefrontal cortex, tended to show less activity.
These scans indicate that sleep loss may lead us to experience heightened responses to negative emotional experiences but leave us without the rational tools to talk ourselves out of the wave of anxiety.
The good news is that the study suggests getting a good night of sleep is a way to ensure that the prefrontal cortex gets the rest it needs to help regulate other areas of the brain. Well-rested subjects tended to have slightly lower anxiety scores depending on the amount of non-rapid eye movement (REM) sleep, called slow-wave sleep, they got per night.
“Our idea is that exactly during non-REM sleep, during deep sleep, these regions are being effectively restored,” says Ben-Simon. “And we found that it’s not just how much time you spend, it’s also the quality, the depth of that sleep, which is usually measured by the slow wave activity.”
The lab’s further research is looking to tease apart how these individual slow waves may affect these important brain regions, but for right now they’re working with a pattern that they’ve identified throughout their study. There is more and more evidence that the link between anxiety and sleep may lie in specific regions in the brain:
“We think a lot of these regions are specifically benefitted from deep, non-REM sleep,” she adds.
Researchers continue to be fascinated by sleep and its effects on the brain. A different study, released in January — video is at the top of this article — conducted by scientists at Binghamton University, State University of New York, and published in the Journal of Behavior Therapy and Experimental Psychiatry, elicited results that suggested “that sleep disruption may be associated with a specific impact on cognitive resources that are necessary for the top-down inhibitory control of attention to emotionally negative information.”