Evidence-Based Treatment

Within the past 15 years, the field of psychotherapy has wrestled with how to identify the type and nature of evidence that will allow one to validly determine if and when a treatment is likely to be helpful or harmful. Numerous factors, including concerns expressed both by individual citizens and their political representatives, the diverse and contradictory nature of many claims about psychotherapy efficacy and effectiveness, and the alarming number of instances of damage produced by psychotherapy as reported in the news media, fueled these discussions. The debate over how to define an “effective treatment” in the fields of counseling and mental health has revealed some significant schisms among those who adhere to different methods of researching and practicing psychotherapy and counseling.

While counseling and clinical psychology have always been concerned with identifying the effectiveness of psychotherapy, the topic rose to a visible level when the Society of Clinical Psychology (Division 12 of the American Psychological Association, or APA) initiated a task force to identify treatments for which research evidence on treatment efficacy was available. This task force was initiated in 1993 and issued its first report of empirically validated treatments (EVTs) in 1995, with subsequent reports being presented in 1996 and 1998. Each report contained a list of brand-name treatments that were judged to meet certain criteria of effectiveness for a particular diagnostic group. However, as the list of effective treatments grew with each report, so did the concern both with what treatments were still missing from the list and with how “effectiveness” was judged for those treatments that were listed.

Eventually, more than 150 different models and manuals of treatment were identified by different working groups and professional associations, as being “empirically supported.” Armed with the list of endorsed procedures, clinicians faced a daunting task in their search to provide help to the struggling consumer or to achieve demonstrable levels of competence in order to service those who sought their help.

To address criticisms that the original task force report was too restrictive and exclusionary, the initial term of empirically validated treatments was changed in 1998 to empirically supported treatments (ESTs). This term was thought to be less strident and narrow. Likewise, the criterion of empirical support was expanded from two independent controlled trial comparisons to a requirement that a treatment’s value also should be supported by a preponderance of available scientific evidence. Unfortunately, these modifications did not address the types of concerns that were emerging with the Division 12 effort.

Increasingly, individuals raised concerns that the list of brand-named therapies favored narrow theories over important factors within the relationship and the participants (therapist and client). They argued that these extratherapy factors contributed to change at least as much as did the treatment model itself. Many scholars pointed out that head-to-head comparisons usually found that there were negligible differences among various treatments in the actual amount of change accounted for and that treatments, at best, accounted for only about 10% of the change that was observed in patients over the course of treatment. The scholars and practitioners who raised these concerns asserted the importance of a new way of assessing the nature of effective treatments, one based on an analysis of research on participant and interpersonal contributors to the therapeutic relationship itself.

Empirically Supported Relationships

Concerned with the way ESTs were being identified, Division 29 (Psychotherapy) of APA initiated a task force to look for a complementing alternative that would be more compatible with views regarding the importance of the therapeutic relationship. This task force focused on defining what came to be called empirically supported relationships, or ESRs. The identified empirically supported relationship factors included participant qualities and treatment processes that were conducive to change, but that were not part of most formal models of psychotherapy. The task force members reviewed available literature and constructed a list of variables and qualities that were either “probably” or “possibly” associated with beneficial outcomes. The most promising of these qualities included the therapeutic alliance, empathy, patient resistance, level of functional impairment, goal consensus and collaboration, group cohesion, positive regard, genuineness, and management of counter-transference. Efforts to parse these various factors on the basis of their importance concluded that patient variables (i.e., severity of distress, functional impairment, etc.) account for approximately 25% to 30% of the total outcome variance, the therapy relationship or alliance accounts for a further 10%, the person of the therapist accounts for 8% of total change, and the specific treatment methods employed may add as much as another 8% to the successful prediction of outcomes. While slightly different percentages than these have been suggested by other scholars, using different statistical procedures, the therapeutic alliance is generally accepted as being quite salient as a predictor of change.

These findings did not end the disagreements among proponents of EST and ESR perspectives. Each perspective has been criticized for being too narrowly focused and failing to integrate all or most of the important constructs that have been indicative of benefit. They each have also been criticized for being too wedded to certain research methodologies at the exclusion of other, equally respected ones. Efforts to fashion common ground among these various perspectives have taken one of two directions. They have sought either to expand the nature of the evidence on which “validity” is to be judged, in order to be more inclusive of different methodologies and preferred variables (e.g., the APA 2005 Presidential Task Force on Evidence-Based Practice), or to establish a set of guiding principles that can incorporate and integrate concepts from both EST and ESR perspectives (e.g., The Division 12/North American Society for Psychotherapy Research Task Force on Principles of Effective Change).

The APA 2005 Presidential Task Force on Evidence-Based Practice

The president of APA in 2005 initiated a task force on evidence-based practice as part of his presidential initiative. The task force was charged with addressing three specific issues:

  1. How to incorporate the wide range of empirical evidence into the application of psychology
  2. How to incorporate the roles of scientific findings and clinical expertise in decision making, including the process by which practitioners must choose among and incorporate available research
  3. How to highlight the relative importance of different patient variables in treatment of decision making

After much deliberation and input from multiple groups, the task force concluded with a call to extend the definition of what constitutes “empirical support” to include therapist experience and judgment as well as patient preferences and values. The final report of the task force defines evidence-based practice of psychology (EBPP) as a practice that seeks to incorporate current, empirical, research with clinical expertise in regards to a patient’s individual characteristics, cultural background, and personal preferences for psychotherapy. The new EBPP was distinguished from the old, empirically supported treatments by its encouragement of clinicians to use subjective judgment and personal opinions, along with patients’ expressed preferences and values, whenever available research findings seem to be inadequate to the task of psychotherapy. By this means, the EBPP task force attempted to integrate the treatment method and procedures with a more global process of assessment, case formulation, and the power of the therapeutic relationship.

To accomplish the broad purposes of their mission, the APA’s presidential task force gave special consideration to the roles of three broad classes of variables—research, clinical expertise, and patient variables. Integrating these concepts, they concluded that

  1. It is not sufficient to know that a given treatment works. Clinicians must use their own experience and judgment to determine the applicability, feasibility, and usefulness of the intervention in the local or specific setting where it is to be offered.
  2. Practitioners should consider nontreatment factors that affect treatment outcome, such as the individual therapist, the relationship, and the patient. Good therapists should be able competently to incorporate these different sources of evidence into treatment of decision making.
  3. Clinical expertise is necessary in order to incorporate available research with the characteristics of a particular patient. They defined clinical expertise as the experience and knowledge attained by psychologists through education and training that ultimately results in effective therapeutic practices.
  4. The influence of patient qualities and characteristics should be incorporated into the treatment program and integrated with treatment through the medium of therapist experience and judgment.

The Joint Task Force on Empirically Supported Principles of Therapeutic Change

Two fundamental concerns with the conclusions by the APA’s 2005 presidential task force bolstered the development and foundation of a second task force. The former conclusions were seen as (a) placing unfounded faith in unproven and demonstrably fallible clinical judgment and (b) urging the integration of patient, therapist, relationship, and treatment factors without providing any useful guidance for how this might be accomplished. A task force representing, jointly, the Society for Clinical Psychology (Division 12 of APA) and the North American Society for Psychotherapy Research (NASPR) was convened when members and officers within these groups came to believe that neither EST nor ESR, nor APA’s 2005 presidential task force, offered a clear rationale for how patient, therapist, treatment, and relationship variables were to be balanced and integrated.

The joint task force argued that the emerging EST, ESR, and EBPP perspectives failed to capture the importance of integrating multiple dimensions and processes. Because each of these task forces and working groups emphasized only one set of variables (treatment models, relationship factors, or participant factors) at the relative expense of the others, it was thought that they were poorly positioned for integrating these various domains of influence. Moreover, it was feared that APA’s presidential task force, by making clinician judgment the final arbiter of “effectiveness,” ignored the fallibility of human judgment, the role of emotion in distorting perspectives, and the self-serving nature of professional judgment for which science had been developed. A more objective and integrative method offering delineated directions for applying concepts from the patient, the therapist, the relationship, and the treatment was needed.

The Joint Task Force on Empirically Supported Principles of Therapeutic Change sought the answers to two cardinal questions:

  1. What is known about the nature of the therapy participants, relationships, and procedures within treatment that induces positive effects across theoretical models?
  2. How do factors related to these domains work together to enhance change?

The specific mission of the joint task force included an attempt to distill the influences of participant, relationship, and treatment factors into a set of cross-cutting, empirically supported, and informed principles that were not tied to any one theory or perspective of psychotherapy. Unlike APA’s 2005 presidential task force, the evidentiary bases for the principles were to be founded directly on scientific evidence. To resolve some of the differences between the EST and ESR models, moreover, this task force accepted a broad view of acceptable research methodologies, as long as the methods research was published in credible scientific journals, based on peer review.

Ultimately, 24 senior scholars and 21 associated scholars were chosen to work on the principles task force. These authors were divided into groups, each addressing one domain of the variables (participant factors, relationship factors, treatment methods) and one type of problem for which counseling and psychotherapy may be useful (depression, anxiety, personality disorder, or chemical use disorders). These groups were asked to extract from the previous task force reports, and other major research volumes, all of those treatment outcome studies that represented the particular mix of variable domain and problem area to which they were assigned. They were then to dissect the relevant studies, summarize and tabulate the results, and articulate a set of guiding principles that were supported by a preponderance of the available research and that could inform the therapist in treating patients with a particular problem.

The joint task force compiled a set of 61 principles that served to identify aspects of patients, therapists, relationships, and treatments that contributed in predictable and empirically reliable ways to outcome. Twenty-six of these principles were similar in two or more of the four diagnostic problem areas reviewed. The similarity of these principles across problem areas resulted in their being designated “common” principles. In contrast, 35 of the principles were only identified as being adequately supported in one of the four problem areas and thereby, earned the designation as being “unique” principles.

Twenty-eight of the principles (5 common and 23 unique) described ways that extratherapy qualities of the therapist and patient facilitated change in the successful treatment of various problems. The principles emphasized the value of flexibility, the ability to tolerate ambiguity, and tolerance for one’s own negative responses to others. They also identified prognostic indicators among patients, such as the negative affect observed in those with personality disorder, those who lack adequate social support, those with severe problems, and those with a chaotic history and background.

Eleven of the derived principles addressed the use and value of the therapeutic relationship in facilitating change. Most of these (9 of 11) were common to two or more of the problem areas. These latter principles generally pertained to the use of a collaborative framework and to the therapeutic skill required to develop and maintain the therapeutic alliance.

Twenty-two research-informed principles reflected the effective use of different classes of interventions, each being grouped by the impact it had on psychotherapy process (e.g., directive vs. nondirective, insight vs. symptom change). These principles were almost equally divided among those that were common across different problems (12 of 22) and those that were unique to the type of problem being addressed. These principles were clearly integrative, and many of them described ways to tailor interventions to fit different qualities of the patient and the context in which he or she lives.

Future Directions

The balancing and integration of science and practice in counseling psychology continues to be a work in progress. The hopeful observation is that there is a continuing dialogue among the various stakeholders in this debate and the discourse is likely to be productive.


  1. Castonguay, L. G., & Beutler, L. E. (Eds.). (2006). Principles of therapeutic change that work [Report of the Joint Task Force]. New York: Oxford University Press.
  2. Chambless, D. L., & Hollon, S. D. (1998). Defining empirically supported therapies [Part of a special section on defining empirically supported therapies]. Journal of Consulting and Clinical Psychology, 66, 7-18.
  3. Chambless, D. L., & Ollendick, T. H. (2001). Empirically supported psychological interventions: Controversies and evidence. Annual Review of Psychology, 52(1), 685-716.
  4. Levant, R. F. (2005). Report of the 2005 Presidential Task Force on Evidence-Based Practice. Washington, DC: American Psychological Association.
  5. Nathan, P. E., & Gorman, J. M. (Eds.). (2002). A guide to treatments that work (2nd ed.) [Supplement to the Division 12 Task Force Report]. New York: Oxford University Press.
  6. Norcross, J. C. (Ed.). (2002). Psychotherapy relationships that work: Therapist contributions and responsiveness to patient needs [Division 29 Task Force Report]. New York: Oxford University Press.
  7. Norcross, J., Beutler, L. E., & Levant, R. (Eds.). (2006). Evidence-based practices in mental health: Debate and dialogue on the fundamental questions. Washington, DC: American Psychological Association.
  8. Task Force on Promotion and Dissemination of Psychological Procedures. (1995). Training in and dissemination of empirically validated psychological treatments: Report and recommendations [First Division 12 Task Force Report]. The Clinical Psychologist, 48(1), 3-23.

See also: