Sleepless nights encourage dark thoughts. Poor sleep implies poor mental health.

50 years of sleep research put into perspective

“In our largely sleep-deprived society, quantifying the effects of sleep loss on emotions is critical to promoting psychological health“, immediately explains Dr Cara Palmer from Montana State University (United States), and main author of the study, in a press release. “This study represents the most comprehensive synthesis of experimental research on sleep and emotion to date, and provides strong evidence that periods of prolonged wakefulness, reduced sleep duration, and nighttime awakenings negatively influence functioning emotional of the human being“, she adds.

This work synthesizes no less than five decades of research on lack of sleep and mood, and is based on the analysis of data from 154 studies involving 5,717 participants. Who had their sleep deliberately disturbed by the researchers for one or more nights, were kept awake for a long period, slept less than usual, or were woken up regularly during the night, depending on the experiments. All studies also analyzed at least one emotion-related marker, whether self-reported mood, participants’ response to emotional stimuli, or symptoms of depression and anxiety.

Emotional functioning impacted by lack of sleep

Published in the journal Psychological Bulletin, the results reveal that lack of sleep does not only induce fatigue, far from it. It would also negatively influence emotional functioning, particularly positive moods, and increase the risk of anxiety and depressive symptoms. More concretely, regardless of the experience taken into account, the researchers observed harmful effects on joy, happiness, and satisfaction among the participants in this work, as well as an increase in anxiety symptoms which were notably translated by an acceleration of the heart rate.

“This happened even after short periods of sleep deprivation, such as going to bed an hour or two later than usual or after losing only a few hours of sleep. We also found that lack of sleep increased anxiety symptoms and blunted arousal in response to emotional stimuli“, continues Dr. Cara Palmer.

This study has certain limitations, such as the lack of diversity in terms of age of participants (23 years on average) and cultures (United States and Europe only), but it nevertheless makes it possible to evaluate the impact that the lack of sleep on the mental health of men and women, with the consequences this can have on their personal and professional lives.

A real public health problem

“Research has shown that more than 30% of adults and up to 90% of adolescents do not get enough sleep. The implications of this research for individual and public health are considerable in a largely sleep-deprived society. Industries and sectors exposed to sleep deprivation, such as first responders, pilots, and truck drivers, should develop and adopt policies that prioritize sleep to mitigate risks to functioning and well-being during the day“, concludes the main author of this work.