Getting less sleep reduces enthusiasm.
Getting less sleep makes people miserable
A scientific review has analysed 154 studies on sleeping over more than half a century involving more than 5,700 people aged between seven and 79.
Sleeping less than normal was found to significantly reduce positive feelings and also heightens the risk of feeling anxious and depressed.
Dr. Jo Bower, who led the study from the University of East Anglia, said: "These results matter because people who feel less positive enjoy things like seeing friends, going to exciting 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 effect on mood."