If you've ever noticed yourself feeling more anxious and flustered than usual after a night of bad sleep, you're not just imagining it -- a small new study shows that sleep deprivation can actually fire up certain brain regions that affect our emotional processing, boosting feelings of anxiety.
Researchers from the University of California, Berkeley, found that when a person is sleep deprived, activity in the amygdala and insular cortex brain regions is increased. And these effects are even more amplified in people who are already natural worriers.
"It's been hard to tease out whether sleep loss is simply a byproduct of anxiety, or whether sleep disruption causes anxiety," study researcher Andrea Goldstein, a doctoral student in neuroscience at the university, said in a statement. "This study helps us understand that causal relationship more clearly."
For the study, published in the Journal of Neuroscience, researchers had 18 young healthy adults (all of whom had no diagnosis of an anxiety order, but who had varying ranges of general levels of anxiety) have a good night's sleep, then a night of sleep deprivation. After each night, the participants got brain scans as they underwent an image test.
For the image test, researchers had the participants look at neutral or disturbing images. In order to cause the participants to feel "anticipatory anxiety," they would show a visual cue before each group of images -- a yellow circle, meaning they would see just a neutral image; a red minus sign, meaning they would see a disturbing image; or a white question mark, meaning they would see either a distressing or a neutral image.
Researchers found that when the study participants were sleep deprived and undergoing the image test, they had exceedingly high activity in the amygdala and insular cortex brain regions, compared with when they had had a full night's sleep.
Past research has also shown a relationship the other way around, too -- that stressful, anxiety-inducing events can prompt sleep troubles. WebMD reported in 2007 on a Finnish study, showing that people who previously had no sleep troubles started to experience problems sleeping after a stressful event.