Avasad and Vishad are two conditions mentioned in the Granthas, which can be closely related to depression. Everyone feels low, sad, hopeless, guilty or restless at some time in their lives.
But when these emotions stay with you night and day along with decreased appetite, affected sleep (increased or decreased), inability to be as productive as you used to be, then it might direct to the condition known as Clinical depression.
Though it can be mild, moderate or sever, early diagnosis and treatment have always proved to give best results. Desire to do normal routine tasks gets affected with suicidal thoughts in sever cases. Some unfortunate may commit suicide due to inability to diagnose the depression.