THINKING CRITICALLY Are All Forms of Therapy Equally Effective

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Chapter 13 Treatment of Psychological Disorders
LINKAGES
Does psychotherapy work? (a
link to Introduction to the
Science of Psychology)
A
s you might imagine, most therapists
agree with this assessment, and most
believe that the theoretical approach
and treatment methods they use work better
than those of other therapists (e.g., Giles,
1990; Mandelid, 2003).
T H I N K I N G C R I T I C A L LY
Are All Forms of Therapy
Equally Effective?
■ What am I being asked to believe or accept?
They can’t all be right, of course, and some researchers claim that they are all wrong.
These researchers argue that, in fact, various theories of behavior disorder and the specific treatment methods based on them don’t have much to do with the success of psychotherapy. All approaches, they say, are equally effective. This has been called the
“Dodo Bird Verdict,” after the Alice in Wonderland creature who, when called on to
judge who had won a race, answered, “Everybody has won and all must have prizes”
(Duncan, 2002; Luborsky, Singer, & Luborsky, 1975).
■ Is there evidence available to support the claim?
Some evidence does suggest that there are no significant differences in the overall effectiveness of psychodynamic, humanistic, and behavioral therapies. Statistical analyses
that combine the results of a large number of therapy studies show that the three
approaches are associated with about the same degree of success (Lambert & Bergin,
1994; Luborsky et al., 2002; Luborsky, Rosenthal, & Diguer, 2003; Shadish et al., 2000;
Smith et al., 1980; Weisz, McCarty, & Valeri, 2006).
■ Can that evidence be interpreted another way?
It is possible, however, that evidence in favor of the Dodo Bird Verdict is based on
statistical methods that cannot detect genuine differences among treatments. A statistical analysis that averages the results of many different studies might not reveal
important differences in the impact of particular treatments for particular problems
(Beutler, 2002; Eysenck, 1978; Wilson, 1985; Rounsaville & Carroll, 2002). Suppose,
for example, that Therapy A works better than Therapy B in treating anxiety but that
Therapy B works better than Therapy A in cases of depression. If you combined the
results of treatment studies with both kinds of clients, the average effects of each therapy would be about the same, making it appear that the two treatments are about
equally effective. Differences among the effects of specific treatment procedures might
also be overshadowed by the beneficial common factors shared by almost all forms of
therapy—such as the support of the therapist, the hope and expectancy for improvement that therapy creates, and the trust that develops between client and therapist
(Barber et al., 2000; Martin, Garske, & Davis, 2000; Vocisano et al., 2004). Therapists
whose personal characteristics can motivate clients to change might promote that
change no matter what specific therapeutic methods they use (Elkin, 1999; Hubble,
Duncan, & Miller, 1999).
■ What evidence would help to evaluate the alternatives?
Debate over the question of whether all forms of psychotherapy are about equally effective on the average is likely to continue, but to many researchers, it is the wrong question. They argue that is pointless to compare the effects of psychodynamic, humanistic, and behavioral methods in general. It is more important, they say, to address what
Gordon Paul called the “ultimate question” about psychotherapy: “What treatment, by
whom, is most effective for this individual with that specific problem, under what set
of circumstances?” (Paul, 1969, p. 44).