A survey of 154 studies across 50 years helped pinpoint life's golden rule to having a happy life. Photo / 123rf
A survey of 154 studies across 50 years helped pinpoint life's golden rule to having a happy life. Photo / 123rf
Going to sleep later than you’re meant to could create many problems for your happiness the next day, even if you’re only missing out on one hour of sleep.
A scientific review, covering 50 years of research has revealed that getting an inadequate amount of sleep compared to your normal amount, regardless of the duration, leads to reduced positivity and happiness in individuals.
The review examined 154 studies about sleep deprivation, involving more than 5000 people aged 7 to 79, to reach its conclusions.
A notable decrease in positive emotions, such as enthusiasm and happiness, was observed in individuals who suffered from sleep deprivation.
Individuals experienced the most substantial decline in positive emotions when deprived of four or more hours of sleep compared to their usual amount. Still, any reduction in the usual amount of sleep led to an overall decrease in positive emotions.
Researchers also linked a greater risk of experiencing feelings of anxiety and depression to missing out on your normal amount of sleep, albeit to a lesser extent.
Dr Jo Bower, psychology lecturer at the University of East Anglia, headed the study and explained: “These results matter because people who feel less positive enjoy things like seeing friends, going to exciting events or watching their favourite television show less, which puts them at greater risk of depression.
“They are typically less motivated to socialise, so are at greater risk of isolation and loneliness.
“In our largely sleep-deprived society, people often stay up late, and we don’t want them to be afraid of doing so, but this analysis suggests less sleep will have an affect on mood.”
Getting enough sleep each night is crucial for many reasons. But your overall happiness is largely determined by how consistently you get a good night's sleep. Photo / 123rf
Published in the Psychological Bulletin journal, the scientific review highlighted that the positive emotional state of individuals is predictably most affected by receiving an inadequate amount of sleep, such as pulling an all-nighter or having little sleep over consecutive nights.
However, the researchers also examined the correlations and consequences of sleeping less than your usual amount and experiencing sleep disruption throughout the night.
Fortunately for those with little ones who frequently wake them in the night, experiencing sleep disruption was not found to be linked to a substantial increase in negative emotions. This is not the case with the two other types of sleep loss.
Yet this observation may be due to the limited number of studies available to establish a link between the two.
Sleep restriction, which is receiving less sleep than your usual amount and may result from an change in your sleeping pattern, was also connected to how people reacted emotionally to things.
Experiments included exposing participants to distressing images, such as a person pointing a gun and a snake, or engaging them in stress-inducing tasks, such as solving maths problems mentally.
Those who received less sleep than usual displayed milder and less negative emotional reactions, which suggests that concerns are diminished by receiving inadequate sleep.
Interestingly, an overall lack of sleep or an insufficient amount were both associated with a larger decline in positive feelings than they were with an increase in negative emotions, which include feelings like sadness and unease.
Sleep deprivation leads to an increase in the release of the stress hormone cortisol, further affecting your mood. Photo / 123rf
This may be the result of a larger release of cortisol - a hormone that triggers a stress response in the nervous system - when sleep deprivation occurs.
Cortisol’s effects on the nervous system aid in the production of physical anxiety symptoms. This manifests in ways such as an increased heart rate or tachypnea (rapid breathing).
Furthermore, insufficient sleep disrupts the brain’s production of serotonin, a neurotransmitter also coined a “happy hormone” that plays a crucial role in regulating mood. An inadequate amount of serotonin in the body can lead to feelings of depression. This includes less feelings of happiness and low self-esteem.
Inadequate sleep has been linked to several chronic health problems over the years. Issues such as heart disease, kidney disease, diabetes, hypertension, stroke, sleep apnea, obesity and depression are associated with an insufficient amount of sleep.
Counterintuitively, a lack of sleep can also induce insomnia, a sleep disorder that makes it difficult for individuals to fall asleep or stay asleep consistently.
In the studies examined by researchers, individuals tended to rank their positive emotions on a scale to create data for research use.
“Evolutionarily, positive emotions like enjoyment are good for helping us form social bonds and learn,” said Bower.
“But when we haven’t had enough sleep, our cognitive function is reduced, so we need to prioritise things like processing threats.
“That could be why positive emotions are dialled down, because they do not have a short-term benefit.”
Nevertheless, study participants were in their 20s, potentially influencing their results. The researchers suggested that future studies should incorporate a wider age range for a better understanding of how sleep deprivation affects individuals as they grow older.
