178 CHAPTER 5
Specifi c factors
The characteristics of a particular treatment
or technique that lead it to have unique
benefi ts, above and beyond those conferred
by common factors.
- an opportunity to obtain support, feedback, and advice;
- encouragement to take (appropriate) risks and achieve a sense of mastery;
- hope; and
- a positive relationship.
Common factors, and certain patient characteristics—such as being motivated
to change (Clarkin & Levy, 2004)—can contribute more to having a positive out-
come from therapy than the specifi c techniques used. This means that Carl Rogers
was on to something when he stressed the importance of a therapy relationship that
is supportive and warm. Such qualities can amplify the therapeutic power of the
common factors; however, the magnitude of the effect of common factors depends
on the patient’s specifi c problem (Roth & Fonagy, 2005). If your grief box ther-
apy were effective, it might be because of such common factors and not something
unique to your particular method.Specifi c Factors
The existence of common factors creates a challenge for researchers who are
interested in determining the benefi ts of a particular type of treatment or technique.
These researchers must design studies in which the effects of common factors are
accounted for and the unique benefits of the particular treatment or technique
under investigation can be examined. The characteristics that give rise to these
unique benefi ts are known as specifi c factors. For instance, when researching your
grief box therapy, you might want to investigate whether the process of creating
the grief box is a specifi c factor, providing benefi t above and beyond the common
factors that any therapy provides.
Such research has shown that common factors alone may not be sufficient
to produce benefi ts in therapy for some disorders (Elliott, Greenberg, & Lietaer,
2004; Kirschenbaum & Jourdan, 2005; Lambert, 2004); at least for some disorders,
specifi c factors play a key role in treatment. For example, research results suggest
that for people with OCD, exposure with response prevention (a specifi c factor)
is more important for successful treatment than common factors (Abramowitz,
1997; Chambless, 2002). However, for many disorders, including depression, the
research results suggest that specifi c factors may be only as important as (or even
less important than) common factors in the treatment of mild or moderate cases
(Lambert, 2004). In fact, for some disorders, researchers have found that differ-
ent types of therapy are about equally benefi cial. The leftmost column in Table 5.3
notes specifi c factors—the therapy variables—that are the subject of research target-
ing psychological treatments. (In subsequent chapters, we will discuss research on
treatments for specifi c disorders; such studies typically examine specifi c factors.)Controlling Possible Confounding Variables
with Analogue Studies
Many variables, such as those listed in Table 5.3, can infl uence the outcome of
psychotherapy and may be confounding variables in specifi c studies. For instance,
suppose you decide to undertake a study that compares your grief box therapy
for depression after breakups to an older treatment for depression, such as cogni-
tive-behavior therapy (CBT); you train some therapists at the counseling center to
administer your new treatment, and they are very excited and enthusiastic about
it. Other therapists at the counseling center administer CBT for depression, which
they’ve been providing for years. These therapists may be less enthusiastic in their
manner during therapy. If your new therapy does in fact benefit patients more
than does CBT, a possible confounding variable would be the therapists’ levels of
enthusiasm for the two treatments. That is, it could be the manner in which the new
therapy was provided that was particularly helpful to patients rather than the tech-
nique itself.