The fact that the cause of this change remains obscure may distress the person with depression. If wrong thinking causes depression, then people must feel guilt over their contribution to their condition. Even if positive thinking holds out marvels of hope for the depressed individual, there always remains the fear that old patterns will recur again and bring on the depression. If depression is a physiological condition which has arisen from obscure causes, then the depressed person can put trust in a physical remedy, even though its action may prove somewhat slow. In some cases a depression will suddenly lift.
People carry on with their lives and return to their former selves.
With no change in thought patterns, these individuals remain without depression. This feature of depression may support the view of it as a physiological condition. For some reason it is self-limiting. Mercifully it departs. The early Greeks believed that all mental activity took place in the chest region.