Research and practice in psychotherapy has been deeply influenced by two different approaches:
- the Empirically Supported Treatments (ESTs) movement, due to the development of Evidence Based Medicine (EBM) attitude in the mental health field, and
- the Common Factors perspective, and the importance of common factors in the explanation of the therapeutic process.
These two different approaches are well described by Terence Tracey et al. (2003):
One view is that each model of therapy has distinctive effects on clients. This assumption of distinctiveness leads naturally to the inference that some models are more effective than others with particular client types
A competing and perhaps complementary view is that different theoretical approaches are comparably effective” (p. 401).
ESTs can be tested with randomised controlled clinical trials (Herbert, 2003; Morrison, Bradley, & Westen, 2003);, however there is a growth of studies about the “Common Factors” perspective confirming the notion that all therapies are equally effective — the so-called “Dodo Bird Verdict” (Luborsky et al., 2004; Luborsky & Singer, 1975).
There is emphasis on the economic factors in play when looking at Evidence Based Medicine, and the current "gold standard" seems to be CBT, not just for anxiety disorders (Otte, 2011), but for everything. Yet, there are shortfalls with CBT and as pointed out in that link, some say that the efficacy figures were artificially inflated.
While I can understand the standpoint of those who push for scientific scruitiny of psychotherapeutic approaches, as can be seen in Psychology.SE meta I am also a defender of approaches which have been denounced as purely pseudoscientific and therefore invalid.
Apart from what I covered in my answer in meta, and Sven Hansson's revision of his definition of pseudoscience (Hansson, 1996), are there other arguments, for and against, each side of the debate?
Hansson, S. O. (1996). Defining Pseudoscience and Science In:Philosophy of Pseudoscience: Reconsidering the Demarcation Problem Pigliucci & Boudry (Eds.) Chicago, IL: University of Chicago Press
Readable in Google Books
Luborsky, L., & Singer, B. (1975). Comparative studies of psychotherapies. Is it true that "everyone has won and all must have prizes"? Archives of General Psychiatry, 32(8), 995—1008.
Morrison, K. H., Bradley, R. & Westen, D. (2003). The external validity of controlled clinical trials of psychotherapy for depression and anxiety: a naturalistic study. Psychology and Psychotherapy: Theory, Research and Practice, 76(Pt 2), 109—132.
PMID: 12855059 DOI: 10.1348/147608303765951168
Otte, C. (2011). Cognitive behavioral therapy in anxiety disorders: current state of the evidence. Dialogues in Clinical Neuroscience 13(4), 413—421.
PMCID: PMC3263389 Free PDF: ResearchGate & Archive.org
Tracey, T. J. G., Lichtenberg, J. W., Goodyear, R. K., Claiborn, C. D. & Wampold, B. E. (2003). Concept mapping of therapeutic common factors. Psychotherapy Research, 13(4), 401—413.