BERKELEY, Calif. — Anxiety and stress are universal human conditions, experienced to some degree by everyone at various times in their life. While some are less prone to bouts of anxiety than others, we’ve all felt especially fried after a long day filled with trials and tribulations. Society tells us there are various ways to reduce stress and unwind: have a drink, watch a movie, take a deep breath, etc., but a new study finds the best way to promote a natural, neural “reset” of sorts and relieve anxiety is to fall into a deep sleep.
According to the research team at UC Berkeley, deep sleep, scientifically referred to as non-rapid eye movement (NREM) slow-wave sleep, stabilizes our emotions, promotes highly-synchronized neural movements between synapses, and lowers heart rate and blood pressure. In short, falling into a deep sleep quite literally soothes the brain into a relaxed state, allowing it to reset inter-neural connections and reinvigorate itself.
“We have identified a new function of deep sleep, one that decreases anxiety overnight by reorganizing connections in the brain,” explains senior author Matthew Walker, a UC Berkeley professor of neuroscience and psychology, in a release. “Deep sleep seems to be a natural anxiolytic (anxiety inhibitor), so long as we get it each and every night.”
Overall, this new set of research is among the strongest pieces of evidence ever connecting sleep to anxiety relief on a neural level. Furthermore, the study’s authors believe their findings designate sleep as a natural, non-pharmaceutical alternative for anxiety disorder treatment.
“Our study strongly suggests that insufficient sleep amplifies levels of anxiety and, conversely, that deep sleep helps reduce such stress,” says study lead author Eti Ben Simon, a postdoctoral fellow in the Center for Human Sleep Science at UC Berkeley.
Using MRI technology, as well as other techniques, the research team observed the brain activity of 18 young adults as they viewed “emotionally stirring” videos on two different occasions; once after a full, restful night’s sleep, and then again after staying up all night. Anxiety levels were also measured after each video session via a survey.
Brain scans after the sleepless night revealed that the participants’ medial prefrontal cortex had shut down. This structure usually helps regulate anxiety. Meanwhile, the same brain scans also revealed that participants’ deeper emotional centers were overactive after not sleeping.
“Without sleep, it’s almost as if the brain is too heavy on the emotional accelerator pedal, without enough brake,” professor Walker says.
On the other hand, after getting a full night’s sleep, participants’ anxiety levels dropped considerably. Those who achieved slow-wave NREM sleep for longer periods of time showed even more pronounced drops in anxiety.
Researchers followed up by conducting the same experiment with an additional 30 participants, which produced the same results. Additionally, a third experiment was held. This time, 280 individuals, of a variety of ages, took part in an online study that asked about how their sleep and anxiety levels fluctuated over the course of four days. This set of research revealed that the amount and quality of sleep each person attained each night directly influenced how anxious they felt the next day. Even slight fluctuations in sleep patterns appeared to impact anxiety levels.
“People with anxiety disorders routinely report having disturbed sleep, but rarely is sleep improvement considered as a clinical recommendation for lowering anxiety,” Simon says. “Our study not only establishes a causal connection between sleep and anxiety, but it identifies the kind of deep NREM sleep we need to calm the overanxious brain.”
“The findings suggest that the decimation of sleep throughout most industrialized nations and the marked escalation in anxiety disorders in these same countries is perhaps not coincidental, but causally related,” professor Walker concludes. “The best bridge between despair and hope is a good night of sleep.”
The study is published in the scientific journal Nature Human Behaviour.