"A standard textbook of clinical psychology offers five schools of thought on the subject of depression. It then offers ten competing humanist medical models of depression. Recently non-Christian therapists and counselors have been advocating an eclectic approach – dealing with each case on a pragmatic basis using a combination of several different medical models. Following their example, some Christian counselors have tried to define and treat depression without starting from the biblical model of human nature: man is a creature made in the image of God, living (apart from Christ) in bondage to sin’s power, but capable of being liberated by the cross through the power of the Holy Spirit.
Non-Christian therapists and counselors cannot fully succeed in treating depression because their medical models of the human condition exclude the spiritual aspect of our being. Depression always has a spiritual dimension. God has given a Counselor, the Holy Spirit, to guide us into the truth of our condition and the solution to it."
Source: Campbell, K. (1996). Those ugly emotions: How to manage your emotions (35). Ross-shire, GB.: Christian Focus Publications.