The efficacy of cognitive therapy (CT) in the treatment of many psychiatric disorders, including depression, has been established in a large number of randomized clinical trials (RCTs; Cuijpers et al., 2008
; Butler et al., 2006
; Strunk and DeRubeis, 2001
, Gloaguen et al., 1998
). The RCT methodology is well accepted as the “gold standard” for establishing efficacy (Seligman, 1995
, p. 966). Based on RCT evidence, a number of psychosocial treatments have been designated as “empirically supported therapies” (ESTs) (Chambless and Hollon, 1998
). Often, however, RCTs are conducted in academic settings using procedures that are discrepant from how psychotherapy is most commonly delivered. This includes the use of specially trained therapists, extensive supervision, random assignment to treatment, and restrictive participant inclusion/exclusion criteria. Some have argued that these features of RCTs compromise their clinical validity (Goldfried and Wolfe, 1998
; Westen et al., 2004
). This has led to an increase in focus on questions about the extent to which results of such efficacy trials can be translated into clinical effectiveness, as was captured by a question posed by Carroll and Rounsaville (2007
, p. 851): “Do they [ESTs] work in the real world as well as the ivory tower?”
Researchers have begun to assess the effectiveness of ESTs in non-research settings. One area of concern with such evaluations, however, is the extent to which treatment in the “real-world” has been assessed under clinically representative conditions (Shadish et al., 1997
; Shadish et al., 2000
). Studies of clinical effectiveness range on a continuum of how clinically representative conditions are. Shadish and colleagues have shown that, often, representativeness has been associated with a lower degree of control over research methodology (Shadish et al., 2000
To date, methodological issues have limited the available research knowledge about outcomes in clinical settings. Benchmarking is a method for assessing clinical effectiveness whereby outcomes observed in outpatient samples are compared to those obtained in research studies (McFall, 1996
). Wade and colleagues (1998)
, who reported one of the first uses of benchmarking in the psychotherapy literature, transported cognitive therapy for panic disorder to a community mental health center. Participants seen in this mental health center were shown to have similar treatment outcomes to participants in two efficacy studies. In the depression literature, several studies have employed similar methodologies and suggested few differences in outcomes for depressed participants treated in RCTs versus clinical practice. Persons, Bostrom, and Bertagnolli (1999)
reported that the outcomes of participants with depressive symptoms in a private practice who received cognitive therapy, alone or in conjunction with medication, did not differ from the outcomes of participants receiving those treatments within the context of two randomized controlled trials. One potentially important (and limiting) difference between benchmark samples and clinic samples is method of diagnosis. In this study, participants in the RCTs were diagnosed as having depression via structured diagnostic interviews whereas the private practice participants were diagnosed by unstructured means, with a minimum BDI score substituting a diagnosis of major depressive disorder.
In another study of cognitive therapy in the clinic, Merrill and colleagues (2003)
transported cognitive therapy to a community mental health center. They found that clinic participants evidenced rates of symptom improvement similar to participants in two published RCTs for depression. This provided an excellent indicator of the ability to transport an EST into clinical care, but as clinicians were receiving ongoing intensive supervision in the EST, the findings may not generalize to many practice settings, in which supervision is often not provided.
Minami and colleagues (Minami et al., 2007
; Minami et al., 2008
) compared outcomes from 35 research studies of the treatment of depression to outcomes of depressed participants treated with usual-care psychotherapy treatments within a managed care setting (the exact type of therapy was not reported). Overall, their results indicated that the average outcome in treatment-as-usual settings was similar to those observed in clinical trials. One complicating factor in interpreting these results, however, was that the authors relied on pre- to post-treatment effect sizes to draw their conclusions. Comparisons of this index between samples are affected by differences in the sample variances, such that higher indexes are achieved when pre-treatment variance is constrained, as happens when minimum severity criteria are employed in research studies.
In a large sample of participants with a range of psychiatric disorders in routine clinical practice under the National Health Service in England, Westbrook and Kirk (2005)
reported that participants treated with cognitive behavior therapy responded well, on average. Comparisons were made between the outcomes observed in subsets of depressed and anxious participants and those obtained in relevant clinical trials for those disorders. For depressed participants, the mean post-treatment BDI score for participants in routine care was not different from those in an RCT, but the participants in routine care evidenced a lower recovery rate than participants in the RCT. Unfortunately, participants in the sample were not formally diagnosed, so such subset analyses must be interpreted with caution.
In order to address some of the methodological limitations in the literature to date, this study examines outcomes of CT in a non-protocol outpatient clinic setting at the Center for Cognitive Therapy (CCT) in Philadelphia. It aims to provide evidence of the effectiveness of cognitive therapy under routine clinical conditions and to expand on previous research by including a sample of participants diagnosed using structured clinical evaluations and treated with one treatment modality, cognitive therapy. Treatment in this setting met all of the conditions set forth for clinical representativeness (Shadish et al., 2000
): participants present at the CCT with common psychiatric problems, and are routinely treated with CT. Clients are referred to the center by treatment providers and other health professionals as well as by word of mouth, and clinicians at the center are clinical staff (not researchers). The structure of treatment is weekly therapy sessions, as seen in typical clinical practice. Although participants complete weekly symptom measures as standard procedure and as a clinical tool, treatment and participant outcomes are not expressly monitored, and therapists are free to proceed with treatment idiosyncratically. Participants present with a variety of symptoms and disorders and are not excluded on the grounds of comorbid symptom features. Therapists are not specifically trained immediately prior to treating the participants in this sample, and research is not conducted at the CCT. Therapists are free to apply treatment interventions as they see fit – they do not adhere to a specific manual or treatment guideline, and the length of treatment is open-ended (within the constraints imposed by clients' financial concerns and by the policies of managed care and insurance companies).
In addition to providing data on clinical effectiveness for future research, a second goal of the current study is to compare the outcomes of participants treated in this clinical setting (the CCT) to a benchmark of outcomes of participants treated in a large NIMH-funded RCT of cognitive therapy versus medications for depression (DeRubeis et al., 2005
). Differences between the two samples in baseline participant characteristics will be examined and controlled statistically in outcome comparisons. The DeRubeis et al. study is an ideal comparison group because it was conducted in the same setting in which the CCT operates in, adjacent to the same university campus, receiving referrals from many of the same external treatment providers. The DeRubeis et al. study was also conducted around the same time that participants in the CCT sample were seen for treatment and therapists in the study had prior training from A.T. Beck and colleagues in cognitive therapy. The number of similarities between the CCT and the DeRubeis et al. study enhances the ability to compare the two settings and provides the greatest degree of ability to make inferences about similarities or differences in treatment outcomes.
In terms of specific hypotheses, we predicted that, based on previous research, cognitive therapy under routine conditions at the CCT would be an effective treatment for depression. Further, since results of benchmarking comparisons to date have yielded little evidence of a difference between outcomes in clinical practice and RCTs, we hypothesized that there would be no difference in outcomes between the CCT and RCT sample.