Researchers have known for a while about a connection between insufficient sleep and anxiety. A new study strengthens and quantifies this causal relation and shows that a sleepless night can raise anxiety by up to 30%. Matthew Walker, a professor of neuroscience and psychology at the University of California (UC), Berkeley, along with his colleagues set out to examine the effects of various stages of sleep to treat anxiety in 18 participants. Scientists routinely divided sleep into two broad categories; rapid eye movement (REM) and non-REM sleep.

To measure anxiety levels, the researchers asked a group of 18 young adults to watch emotionally unsettling videos after a full night of sleep and after a sleepless night. After each viewing, the participants completed a standard anxiety questionnaire called the state-trait anxiety inventory. The scientists used functional MRI and polysomnography to scan the brains of the sleeping participants in order to analyze the stages of sleep. The brain scans showed that a certain brain area called the medial prefrontal cortex was deactivated after a sleepless night. Previous studies have suggested that this brain area attenuates anxiety and stress

Furthermore, the study found that anxiety levels decreased after a full night of sleep and that this decline was even more significant in people who spent more time in the deep, slow-wave, non-REM stage of sleep. The study’s lead author also suggests that good sleep should be a clinical recommendation for treating anxiety. The lab experiments confirmed that people who experienced more deep sleep at night had the least anxiety the following day. An online survey confirmed that the amount and quality of sleep that people got reliably predicted their anxiety levels the following day. 

Prof. Walker briefed,” We have identified a new function of a deep sleep, one that decreases anxiety overnight by reorganizing connections in the brain. Deep sleep seems to be a natural inhibitor to treat anxiety, long as we get it each and every night,”