Everyone has sad or irritable mood from time to time. It is normal to feel
sad, down, or irritable after something goes wrong, such as a loved one dying, a bad mark on a test, a conflict with a friend or family member, or after receiving bad news. Usually, when the situation improves, your mood will get better. If your mood doesn’t improve or if it worsens, it could be a sign of depression. Depression is more than just being moody.
When you are depressed, you feel sad or irritable most of the time. These
feelings last for at least two weeks. Depression usually comes with other
difficulties, such as having less interest or enjoyment in things, having
difficulties with eating or sleeping, having low energy, and having thoughts
about death or suicide. Depression can affect your day-to-day life and ability to function.