The effects of sleep on negative mood. Both correlational and experimental (yes, researchers actually bring people into labs and keep them up all night… any volunteers?) evidence suggest that when people are sleep deprived, they feel more irritable, angry and hostile. Sleep loss is also associated with feeling more depressed. In addition, sleep deprivation seems to be associated with greater emotional reactivity --people who suffer from sleep loss are especially likely to react negatively when something doesn’t go well for them.