People who sleep late at night, kindly take note. Researchers have found that after a night of shorter sleep, people react more emotionally to stressful events the next day -- and they don't find as much joy in the good things.
For the study, published in the journal Health Psychology, the research team looked at how sleep affects our reaction to both stressful and positive events in daily life.
"When people experience something positive, such as getting a hug or spending time in nature, they typically feel happier that day," said study researcher Nancy Sin from the University of British Columbia in Canada.
"But we found that when a person sleeps less than their usual amount, they don't have as much of a boost in positive emotions from their positive events," Sin added.
Using daily diary data from a national US sample of almost 2,000 people, the research team analysed sleep duration and how people responded to negative and positive situations the next day.
The participants reported on their experiences and the amount of sleep they had the previous night in daily telephone interviews over eight days.
People also reported a number of stressful events in their daily lives, including arguments, social tensions, work and family stress, and being discriminated against.
When people slept less than usual, they responded to these stressful events with a greater loss of positive emotions.
This has important health implications: previous research by Sin and others shows that being unable to maintain positive emotions in the face of stress puts people at risk of inflammation and even an earlier death.
Chronic health conditions -- such as heart disease, diabetes and cancer -- are prevalent among adults, especially as we grow older.
Past research suggests that people with health conditions are more reactive when faced with stressful situations, possibly due to the wear-and-tear of the physiological stress systems.
"We were also interested in whether adults with chronic health conditions might gain an even larger benefit from sleep than healthy adults," said Sin.
"For those with chronic health conditions, we found that longer sleep -- compared to one's usual sleep duration -- led to better responses to positive experiences on the following day," Sin revealed.
The research team hoped that by making sleep a priority, people can have a better quality of life and protect their long-term health.
