This is due to tension
The main reason for depression is not going to school and work. Such a person tries to avoid many kinds of activities. This happens because depression takes all the energy and all the time of that person.
The energy level of a person suffering from depression reaches so low from this disease that even getting up from bed is equivalent to running in a marathon. Such a person is not able to mingle with anyone and also faces trouble in sleeping.
Perhaps you would never have thought that overwork can also be a symptom of depression. But many people find themselves immersed in work in order to hide their emotions and run away from related problems.