Science confirms: a lack of sleep can make us angry

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  • If you are constantly feeling annoyed by everything, it's time to evaluate your sleep quality
  • Researchers found that there is a concrete link between lack of sleep and negative emotions
  • Sleep is not only vital for our physical, but also our emotional wellbeing

Sleep is vital for making us feel rested and energised the next day, and for middle-aged adults, sleeping less than six hours a night can be linked to a decline in brain function and compromised quality of life.

If you struggle to sleep, you're probably familiar with feeling groggy, irritable and angry. Now, new research published in the journal Sleep – the official publication of the Sleep Research Society – sheds light on how lack of sleep influences and contextualises emotions like anger.

Lost sleep equals anger

The researchers analysed daily diary entries of 202 college students who tracked their sleep, daily stressors and anger levels over one month. It was clear that students experienced more anger when they'd had less sleep the night before.

The researchers also performed lab experiments which involved 147 community residents. Some of them were ordered to maintain their regular sleep patterns, while others had to reduce their sleep by five hours across two nights. Their anger levels were assessed by exposing them to irritating noises.

It was no surprise that those who had more sleep reacted less badly to irritating noises and reported lower anger levels after two days. The individuals with disrupted sleep, however, showed increased anger at the irritating noises.

Compelling evidence

According to the study authors, these results provide compelling evidence that lost sleep amplifies anger, not only in laboratory conditions, but also in everyday life.

The researchers also wrote that there is value in examining specific emotional reactions such as anger in the context of sleep deprivation.

"The results are important because they provide strong causal evidence that sleep restriction increases anger and increases frustration over time," said Zlatan Krizan, who has a doctorate in personality and social psychology and is a professor of psychology at Iowa State University in Ames, Iowa. "Moreover, the results from the daily diary study suggest such effects translate to everyday life, as young adults reported more anger in the afternoon on days they slept less."

Are you not getting enough sleep lately?

During the current Covid-19 pandemic, sleep deprivation because of anxiety has become prevalent. Good sleeping patterns are, however, not only important for your physical well-being and productivity, but also for maintaining a sound mental state.

"Now more than ever, we need to get good sleep," Dr Amy Guralnick, a pulmonologist at Loyola Medicine in Chicago mentioned in a previous Health24 article. "Sleep can help our immune system function at its best. Getting a good night's sleep also helps us to think clearly and problem-solve better."

If you are currently struggling to sleep, here are some tips that may help:

  • Make a sleep schedule and stick to your routine, especially if you are currently working from home.
  • Avoid technology with a backlight in the hours before bedtime. ("Your brain thinks that the light coming from those is daylight and it will suppress the release of a hormone called melatonin, which helps you to sleep," Guralnick explained.)
  • Write your feelings down in a journal if you are currently experiencing stress and anxiety.
  • Use your bed only for sleep and not for working or eating.
  • Get up and do something else if you take longer than 20 minutes to fall asleep.
  • Make time for exercise or any form of physical activity during the day, as this will make your body feel tired and help you fall asleep.
  • Avoid caffeine, sugar and alcohol several hours before bedtime, as these stimulants may cause restless sleep.

READ | Sleep troubles hit healthcare workers during pandemic

READ | Banishing pandemic worries for a good night's sleep 

READ | First good evidence that brain hits "replay" when you sleep

Image credit: Ketut Subiyanto from Pexels 

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