Depression is a mental disorder that manifests itself through symptoms like depressed mood, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, low energy, and poor concentration. In a severe case of depression, the individual suffering from depression may resort to committing suicide. These problems can become chronic or recurrent and lead to substantial impairments in an individual’s ability to take care of his or her everyday responsibilities.

There are two kinds of this illness: Major depression, or dysthymia which affects mood; and Manic depression or bipolar illness, when feeling low and depressed alternates with recklessness.