Your mood is directly affected by the quality of sleep you are having on day to day basis. You are smart enough to observe it for yourself that after a sleepless night you may be more irritable, short-tempered, and vulnerable to stress. Only a good night’s sleep in the comfort of your own bed will return your mood to normal.
Sleep loss is often associated with feeling depressed.
You can’t fall asleep because your are depressed or is it the other way around?
You are depressed because you are not getting enough quality sleep. Some research suggest that sleep deprivation enhances negative mood due to increased amygdala activity (a brain structure integral to experiences of negative emotions such as anger and rage) and a disconnect between the amygdala and the area of the brain that regulates its functions. So people who suffer from sleep loss are especially likely to react negatively when something doesn’t go well for them. So lack of sleep will make you angry, irritated and negative and will reduce your ability to regulate those emotions.