Depression is often like ocean. You cannot understand the depth at any point of time. The best way to handle it is to swim your way through the problem. Depression is often allowed to grow and at one point of time it becomes difficult to handle it. The fellow under depression often feels he or she is let down or a total failure. Measuring Depression is again a big problem.
Depression comes often when we fail in a big way. I will share a personal experience of my family member. She loved a boy but was refused by him to get married. She felt she is a waste and big failure. She started to think that How can I be a failure. She started working her way to achieve him by pressing her parents. It lead to psycho problems and she became unbalanced.
It took me nearly 6months time to make her parents understand that she has mental illness. Then she had to be taken to a Psychiatric whom cured her 6 months time. She was simply made to understand the reality.
The best way to cure depression is to understand the reality. You must make them understand failing or not getting what they want is phase of life. Whenever we fail we have to weigh the options how much of benefit it is going to be for us in making attempts to get success.
Make sure that you swim well during depression and also understand the threats you have in ocean.