Eating well and exercising regularly but not getting the appropriate amount of sleep could mean you are probably only wasting your effort. It is because sleep plays a crucial role in our health, yet many of us still choose not to pay much attention to its importance.
It has been well-established by previous research that lack of sleep can result in adverse effects on overall health outcomes, including susceptibility to certain diseases, proneness to accidents, long-term and serious health problems, and even extend to outward appearances such as premature wrinkles and dark undereye circles.
Sleep deprivation may also lead to increased stress levels and other mental health issues like anxiety which could affect a person’s ability to perform daily life activities. In a study from the University of California, Berkeley, the researchers found a way to rewire anxious brains through a particular type of sleep known as non-rapid eye movement (NREM) slow-wave sleep. This article will explore the study’s interesting insights on how sleep may help calm and reset the anxious brain.
Sleep disruption is a well-known characteristic of all anxiety disorders, with lack of sleep amplifying anxiety through a dose-effect manner. Although the relationship between sleep loss and anxiety is well documented, researchers from the University of California, Berkeley, aimed to add and strengthen the body of knowledge on the said topic by focusing on three things.
First, they investigated the underlying mechanism of why and how a lack of sleep increases anxiety in humans. Second, they determined whether specific sleep features, such as their stages and physiology, beneficially prevent increased anxiety linked with lack of sleep. Third, they examined whether a subtle, common lack of sleep within an individual, from one night to the next, results in subsequent increases in anxiety daily.
The researchers conducted various experiments using functional MRI and polysomnography, among other measures. They scanned the brains of 18 young adult participants as they viewed emotionally stirring video clips after a full night of sleep and again after a sleepless night. Anxiety levels were measured through a questionnaire known as the state-trait anxiety inventory.
The brain scans showed that after a night of no sleep, there was a shutdown of the medial prefrontal cortex, which normally helps keep our anxiety in check, while the brain’s deeper emotional centers were overactive.
From this, the researchers established that one night of sleep deprivation triggered a significant increase in anxiety in otherwise healthy participants.
On the other hand, after having a full night of sleep, the participants had a significant decline in their anxiety levels, particularly for those who experienced more slow-wave NREM sleep. This finding suggests that deep sleep has restored the brain’s prefrontal mechanism, which regulates our emotions, lowering emotional and physiological reactivity and preventing increased anxiety levels.
The researchers strengthen their findings by replicating the results in a study of another 30 participants. The results also demonstrated that those who got more nighttime deep sleep had the lowest anxiety levels the next day.
The researchers also conducted an online study tracking 280 individuals of all ages regarding how their sleep and anxiety levels changed within four consecutive days. From here, they found the amount and quality of sleep the participants got from one night to the next affected how anxious they would feel the next day.
Sleep disruption among people with an anxiety disorder has been well reported, but studies considering sleep improvement as a clinical recommendation for lowering anxiety have been scarce. The study establishes the causal connection between sleep and anxiety and determines the kind of deep NREM sleep needed to calm the overanxious brain. This research provides one of the strongest neural links between sleep and anxiety, which provides a new window for future research to improve further and understand how sleep is beneficial to relieving or minimizing other mental illnesses.
Ben Simon, E., Rossi, A., Harvey, A. G., & Walker, M. P. (2019). Overanxious and underslept. Nature Human Behaviour, 4(1), 100–110. https://doi.org/10.1038/s41562-019-0754-8
