Clients often come to coaches because of dissatisfaction with an area of their lives, sometimes however there is an underlying problem that needs to be identified and resolved first...depression. Depression is in fact one of the most common reasons for dissatisfaction, and it is outside of the coaches remit to deal with clients who are medically depressed.
This assessment is useful for identifying clients who are Clinically Depressed rather than just unhappy, and the results can be used to advise a client to seek the right kind of support for their problems, rather than assuming that the coach can help.