• Lack of sleep makes you more anxious
• Deep sleep reduces anxiety
• Important brain networks are reorganized during the night
• Heart rate and blood pressure decreases during non-REM sleep
Whether everyday worries or deep-rooted existential fears: there are many reasons for not being able to relax at night. Deep sleep phases in particular can help the brain to cope with fear – according to a study by UC Berkeley in California. At the same time, lack of sleep is said to make people more susceptible to anxiety.
As one of the basic emotions, fear is part of human beings and fulfils its purpose. However, if not adequately mastered, it can have a significant impact on social and professional life, and also health. For this reason alone, it is worth proactively dealing with fear in order to reduce it. Apart from various therapeutic forms of treatment, we have a particularly valuable means available every night at no additional cost: sleep.
Study discovers: deep sleep reduces anxiety naturally
Regarding anxiety, sleep is crucial in two ways: on the one hand, lack of sleep can promote inner restlessness and susceptibility to anxiety by up to 30%, on the other hand, deep sleep in particular can reduce this anxiety. That was the conclusion of a study published by UC Berkeley in California in November 2019. This not only clarified the close connection between sleep and fear, but also made the discovery of a new function of deep sleep possible: “By reorganizing networks in the brain, anxiety is reduced overnight,” says Matthew Walker, professor of neuroscience and psychology. According to Prof. Walker, deep sleep is a natural anxiolytic, i.e. an anxiety reliever – provided you experience it every night.
Brain activity changes due to lack of sleep
For the study, 18 young adults were shown emotionally disturbing videos and their brains were simultaneously scanned using functional MRI. This situation was carried out under two different conditions: once after a good night’s sleep, another time after a night with sleep deprivation. The fear experience was also surveyed after each session. The result: after a sleepless night, activity in the medial prefrontal cortex was greatly reduced. This area is usually instrumental in regulating anxiety. At the same time, increased activity was found in the deeper emotional centres of the brain. However, when the test subjects slept well, the MRI scanning showed a significant decrease in the level of anxiety. This difference was particularly noticeable among those who had enjoyed more deep sleep with long non-REM sleep phases.
Anxiety disorders increase in industrialized countries due to lack of sleep
The scientists’ explanation: deep sleep restored the prefrontal mechanism, which reduced emotional and physiological reactivity and prevented an escalation of the anxiety state. In non-REM sleep, neuronal vibrations are also synchronized, heart rate and blood pressure decreases. These insights also come to bear at the social level: according to Prof. Matthew Walker, one can assume that the common occurrence of increasing lack of sleep and the widespread dissemination of anxiety disorders in most industrialized countries is no mere accident, but that there is a causal factor here too.
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