Sleep loss not only produces fatigue
but can undermine emotional functioning, decrease positive moods and put us at greater
risk for anxiety symptoms, according to a study published in the Psychological
Buttin by the American Psychological Association that summarizes over 50 years
of research on sleep deprivation and mood.
“In our largely sleep-deprived
society, quantifying the effects of sleep loss on emotions is critical to
promoting psychological health”, said study lead author Cara Palmer of Montana
State University (USA).
“This study represents the most comprehensive
synthesis of experimental research on sleep and emotion to date, and provides
strong evidence that prolonged periods of wakefulness, shortened sleep duration,
and nocturnal awakenings negatively influence human emotional function”, add.
Palmer and her colleagues, including
co-lead author Joanne Bower, a PhD at the University of East Anglia, analyzed
data from 154 studies conducted over five decades, involving a total of 5,715
participants.
In all of those studies, researchers
interrupted participants’ sleep for one or more nights. In some experiments,
participants were kept awake or an extended period. In others, they were allowed
to sleep fewer hours than usual, and in others they awakened periodically throughout
the night.
Each study also measured at least on
emotion-related variable after the sleep manipulation, such as participants’
self-reported mood, their response to emotional stimuli, and measures of depression
and anxiety symptoms.
Overall, the researchers found that
all three types of sleep loss caused participants to experience fewer positive
emotions, such as joy, happiness and satisfaction, as well as increased anxiety
symptoms, such as increased heart rate and increased worry.
“This occurred even after short
periods of sleep loss, such as staying up an hour or two later than usual or
after losing only a few hours of sleep”, Palmer explains. “We also found that
sleep loss increased anxiety symptoms and reduced arousal in response to emotional
stimuli.
The results for depression symptoms
were lower and less consistent, as were those for negative emotions such as
sadness, worry and stress.
One limitation of the study is that
most of the participants were young adults (mean age was 23 years), so
according to the researchers, future research should include a more diverse
sample of ages to better understand how sleep deprivation affects to people of
different ages.
Other lines of research might include
examining the effects of multiple nights of sleep loss, studying individual
differences to find out why some people may be more vulnerable than others to the
effects of sleep loss, and examining the effects of sleep loss across different
cultures, as most of the research in the current study was conducted in the
United States and Europe, according to researchers.
“Research has revealed that more
than 30% of adults and up to 90% of adolescents do not get enough sleep”, says
Palmer. “The implications of this research for individual and public health are
considerable in a society at large measure of sleep deprivation”.
It adds that “industries and sectors
prone to sleep loss, such as first responder, pilots and truck drivers should develop
and adopt policies that prioritize sleep to mitigate risks to daytime function
and well-being”.