As a prospective client searches for a psychotherapist, numerous questions may spring to mind. How experienced is the therapist? Has he helped people with problems like mine? Is she someone I can relate to? Yet it may not occur to clients to ask another one: What type of therapy does the clinician deliver? People often assume that the brand of therapy offered is irrelevant to the effectiveness of treatment. Is this assumption correct?
Psychologists do not agree on whether the “school” of therapy predicts its effectiveness. In a survey in 2006 by psychologists Charles Boisvert of Rhode Island College and David Faust of the University of Rhode Island, psychotherapy researchers responded to the statement that “in general, therapies achieve similar outcomes” with an average score of 6 on a 7-point scale, indicating strong agreement. In contrast, psychologists in practice averaged a rating of 4.5, signifying that they agreed only moderately with that position.
As we will discover, both camps can justify their point of view. Although a number of commonly used psychotherapies are broadly comparable in their effects, some options are less well suited to certain conditions, and a few may even be harmful. In addition, the differences among therapies in their effectiveness may depend partly on the kinds of psychological problems that clients are experiencing.
Tale of the Dodo Bird
At least 500 different types of psychotherapy exist, according to one estimate by University of Scranton psychologist John Norcross. Given that researchers cannot investigate all of them, they have generally concentrated on the most frequently used approaches. These include behavior therapy (altering unhealthy behaviors), cognitive-behavior therapy (altering maladaptive ways of thinking), psychodynamic therapy (resolving unconscious conflicts and adverse childhood experiences), interpersonal therapy (remedying unhealthy ways of interacting with others), and person-centered therapy (helping clients to find their own solutions to life problems).
As early as 1936, Washington University psychologist Saul Rosenzweig concluded after perusing the literature that one therapy works about as well as any other. At the time, many of the principal treatments fell roughly into the psychodynamic and behavioral categories, which are still widely used today. Rosenzweig introduced the metaphor of the Dodo Bird, after the feathered creature in Lewis Carroll's Alice in Wonderland, who declared following a race that “everyone has won, and all must have prizes.” The “Dodo Bird verdict” has since come to refer to the claim that all therapies are equivalent in their effects.
This verdict gained traction in 1975, when University of Pennsylvania psychologist Lester Luborsky and his colleagues published a review of relevant research suggesting that all therapies work equally well. It gathered more momentum in 1997, when University of Wisconsin–Madison psychologist Bruce E. Wampold and his co-authors published a meta-analysis (quantitative review) of more than 200 scientific studies in which “bona fide” therapies were compared with no treatment. By bona fide, they meant treatments delivered by trained therapists, based on sound psychological principles and described in publications. Wampold's team found the differences in the treatments' effectiveness to be minimal (and they were all better than no treatment).
One explanation for the Dodo Bird effect is that virtually all types of psychotherapy share certain core features. In a classic 1961 book the late psychiatrist Jerome Frank of the Johns Hopkins University argued that all effective therapies consist of clearly prescribed roles for healer and client. They present clients with a plausible theoretical rationale and provide them with specific therapeutic rituals, he wrote. They also take place in a setting, usually a comfortable office, associated with the alleviation of distress. Later writers elaborated on Frank's thinking, contending that effective therapies require empathy on the part of the clinician, close rapport between practitioner and client, and shared therapeutic goals.