A field doesn't need to follow the scientific method to be effective, but the results will vastly vary according to patient and the professional.
Sad people are detached from reality and let their own life narrative obfuscate what is possible now, the define themselves by whatever happened instead of the attributeless now, the perspective of the depressive fag is that therapist is only cheering you up, but he is introducing a bit of objectivity in your lief. Depressive fags always deal with absolutes, and absolutes are product of emotion.