http://lesswrong.com/lw/2j/schools_proliferating_without_evidence/ and http://lesswrong.com/lw/94t/meta_analysis_of_writing_therapy/ seem relevant.
If you want more detailed refs including the claim that the particular school matters much less than the quality of the therapist (with an honorable exception for CBT), http://counsellingbooks.com/bibliography/theory-and-research/general-and-comparative.html#LambertBergin_1994 http://counsellingbooks.com/bibliography/theory-and-research/general-and-comparative.html#BeutlerEtAl_1994 are relevant.
http://lesswrong.com/lw/2j/schools_proliferating_without_evidence/ and http://lesswrong.com/lw/94t/meta_analysis_of_writing_therapy/ seem relevant.
If you want more detailed refs including the claim that the particular school matters much less than the quality of the therapist (with an honorable exception for CBT), http://counsellingbooks.com/bibliography/theory-and-research/general-and-comparative.html#LambertBergin_1994 http://counsellingbooks.com/bibliography/theory-and-research/general-and-comparative.html#BeutlerEtAl_1994 are relevant.