The Scientific Background of Psychotherapy
- Much has been written about the scientific background or the "science" of psychotherapy.
There are two main differing views about topics in science: is it a 'natural' science (like physics, chemistry, biology and physiology) or a 'social' science, that studies human behaviour, social patterns, and the humanities. The natural (or 'hard') sciences rely on quantifiable empirical data, the scientific method, and focus on accurcy and objectivity. The softer sciences cannot make precise predictions, rely much more on probability, and are concerned with numerous interacting variables, some of which are not quantifiable, or with which there are difficulties with the collection of data. A third category, applied science, takes knowledge from one or more natural scientific fields and tries to use these to solve practical problems (like in medicine).
- Whilst nearly all would agree that psychotherapy, along with similar disciplines like social psychology, group psychology and clinical psychology, falls into the category of a social science, however, there then comes a huge argument about which aspects of the 'scientific method' are properly applicable. We cannot treat humans like laboratory mice; the presence of an observer almost always changes the result; observers are not neutral and objective; social & perceptual differences change radically; etc. Medicine, usually categoriesed as an an 'applied science, often finds itself in a somewhat similar dilemma: it takes information from the 'life' sciences biology, physiology, (neuroscience, immunology, etc.) and tries to apply it to people in everyday life.
- When methods of psychotherapy are scrutinised (i.e. the application of the science), the parameters of a 'natural' science (e.g. Randomised Controlled Trials (RCTs) - eminently suitable for research into the efficacy of drugs, etc.) are often applied, possibly inappropriately. Yet organisations like NICE (UK National Institute for Health & Clinical Excellence) 'tests' methods of psychological / psychotherapeutic treatment with almost the same criteria as it does for pharmacological drugs: thus 'evidence-based' psychotherapies include CBT, Mindfulness practice, EMDR, etc. but not many other forms of psychotherapy.
- The two main tests of whether a (method of) psychotherapy is 'scientific' are efficacy (is it effective; does it produce the desired effect; does this always happen: internal validity and replicability) and effectiveness (how capable of being effective is it; what is the extent of any benefits; how long do the benefits last: external validity and generalizability).
- Efficacy studies consider "the results of a systemic evaluation of the invervention in a controlled clinical research context" (Barlow (1996, p. 1051) and are deemed to be the most important scientifically, and this is where RCTs are often used. They are 'randomised' in that patients with the same diagnosis are randomally allocated different forms of treatment: this (sort of) elimates having a control group, that are not treated, as this is increasingly being seen as unethical. People with a different diagnosis or multiple disorders are excluded. Participating therapists are given detailed instructions about how to perform the therapy (the therapy is 'manualised'), which eliminates the possibility of doing this with several psychotherapies; and the trials are 'blind' trials (where the researchers don't know what method of psychotherapy is used); and sometimes the efects are evaluated for a while after the therapy has ended. Such RCTs are time-consuming, expensive and have a number of limitations, yet - without doing these trials - a method of psychotherapy is often not deemed as having a sufficent 'evidence-base' for efficacy.
- Effectiveness studies have "to do with the applicability and feasability of the intervention in the local setting where the treatment is delivered" and are designed "to determine the generalizability of an intervention with established efficacy" (Barlow, 1996, p. 1055) and so they look at how much benefits are gained from actual real-life, psychotherapy and how long these effects last. Patients already engaged in psychotherapy, or who have finished psychotherapy are surveyed as to the details of their 'treatment' (a medical concept) and their impressions of its effectiveness. There are no restrictions on the therapy, nor selections about who gets therapy, or not. There are no control groups and no placebo therapies. People with multiple disorders are included. The therapists don't necessarily know that their patients are part of a study. Effectiveness studies can be lower cost and done with wider populations and long-term patients. In fairness, there are some problems with effectiveness studies, patients self-select themselves to enter therapy and also to partake in the survey (or not). There is no randomisation. They also rely on the retrospective observations and feelings of the participants; some time may have elasped and responses are not necessarily reliable.
- One of the major studies on the efficacy and effectiveness of psychotherapy was by Seligman [Seligman, M. (1995). The effectiveness of psychotherapy: the Consumer Reports study. American Psychologist, 30(12), pp. 965-974 (available here)]. He concluded that the advantages of effectiveness studies outweigh their limitations and that effectiveness studies are undervalued and underused by psychotherapy researchers. Another comparative study is by Nathan, P.E., Stuart, S.P. & Dolan, S.L. (2000). Research on psychotherapy efficacy and effectiveness: between Scylla ad Charybdis? Psychological Bulleting, 126(6), pp. 964-81) (available here). There are many other such papers, some within various modalities.
- There is another, more philosophical, perspective. Husserl, a sigificant philosophical thinker in this field and the founder of the 20th century school of phenomenology, declared that mental and spiritual 'realities' possess their own reality, independent of any physical basis, and that a science of the mind ('Geisteswissenschaft') must be established on as scientific a foundation as the natural sciences have managed. He believed that experience is the source of all knowledge and that empiricism was limiting: "It is my conviction that intentional phenomenology has for the first time made spirit as spirit the field of systematic scientific experience, thus effecting a total transformation of the task of knowledge."
- When psychotherapy methods are compared (comparative meta-analysis outcome studies), the 'common factors theory' proposes that different theoretical and evidence-based approaches have several common components and that these are actually more significant than compnents that are unique to each approach. This opposes the medical model that hypothesises that the efficacy of psychotherapydepends on specific critical ingredients for specific problems. This 'common factors' hypothesis (known as the 'Dodo-bird hypothesis' (from Alice in Wonderland) because "everybody has won, and so all must have prizes").
- So far, comparisons between different treatmentsfor similar disorders and treatments for different disorders have not shown the superiority of one method over another [Imel, Z. & Wampold, B. (2008). The importance of treatment and the science of common factors in psychotherapy. In: Handbook of Counseling Psychology (4th ed.) (pp. 249-262). J. Wiley & Son; Smith, M.L. & Glass, G.V. (1977).Meta-analysis of psychotherapy outcome studies. American Psychologist, 32(9), pp. 752-760; and also Wampold et al. (1997).A meta-analysis of outcome studies comparing bona fide psychotherapies: Empirically "all must have prizes." Psychological Bulletin, 122(3), pp. 203-215.]
- The 'common factors' theory demonstrates over and over again, that the key factor is the strength of the therapeutic relationship between therapist and patient/client (the strength and nature of the 'bond'); shared information and experience; and the commitment of the patient/client to the therapy. everal sStudies suggest that such common factors account for between 30% - 70% of therapy outcomes.
(For an analysis [abstracts] of similar research projects, please go here). Again, there are many such similar meta-analyses.
- Some criticisms of this 'common factors' theory is that though all these factors are necessary, they are not sufficient to demonstrate client change; the theory does not account for individual techniques and therapists'behaviour; these 'common factors' are nothing more than a warm relationship, and though this is important, it is not the only common factor; and that (finally), the common factors theorey is not scientific, especially in comparison with the 'medical' model.
- As mentioned elsewhere, the EAP is committed to developing a scientifically-based profession of psychotherapy. To this end, it only supports methods (maintreams, modalities) of psychotherapy that have gone through a process of establish their 'scientific validity'. Each method of psychotherapy has to provide substantive answers to the EAP's "15 Questions" on Scientific Validity. These questions are available here. There is a peer assessment process conducted within the European Wide Organisations Committee. It is acknowledged that this is more of a process of political acceptance, than an assessment of the scientificity of a modality of psychotherapy. About 40 modalitieshave gone through this process.
- The Society for Psychotherapy Research, an international multi-disciplinary scientific association, holds both international (and regional) conferences and has an excellent journal (see here). Many of these issues are debated there and in other similar psychotherapy journals.