certain types of psychological problems. However,
no one form of psychotherapy or intervention is
superior for all problems.
Certain features or characteristics are common
to all forms of therapy, including the expert role of
the therapist, the relationship or therapeutic alli-
ance, the building of competence, the release of
anxiety or tension, and the expectation of change.
Although specific characteristics of the patient and
of the therapist may influence outcome, such rela-
tionships appear to be multidimensional and com-
plex. Interestingly, many commonly held beliefs
regarding the relationships between patient and
therapist factors and psychotherapy outcome are
not supported by research.
Psychotherapy research is aimed at assessing
whether or not certain interventions are effective
with specific client populations, what factors seem
relatedtochange,andhowsuchchangecanbe
brought about. More recent studies examine whether
a specific therapy is useful with patients with specific
psychological problems (e.g., specificDSM-IVdiagno-
ses). In addition, clinical psychologists have begun to
examine more thoroughly the relative benefits of psy-
chotherapy versus medication for certain conditions
and of combined therapy/medication treatments.
Finally, research has helped shape practice guidelines
that incorporate empirically supported treatments. In
the future, clinical psychologists are likely to be using
manual-based treatments with increasing frequency.KEY TERMS
attention only control groupA control group
whose members meet regularly with a clinician but
receive no“active”treatment.
catharsisThe release of emotions.
common factorsA set of features that char-
acterize many therapy orientations and that may be
the source of the positive changes effected by
psychological treatment.
control groupIn psychotherapy research, the
group that does not receive the treatment under
investigation.
depth of a problemThe changeability of a
condition or behavior. (The“deeper”the condi-
tion, the less changeable it is perceived to be.)
effect sizeThe size of the treatment effect
(determined statistically).
effectiveness studiesStudies that emphasize
external validity and the representativeness of the
treatment that is administered. A treatment is
considered effective to the extent that clients
report clinically significant benefit from the
treatment.
efficacy studiesStudies that place a premium on
internal validity by controlling the types of clients
in the study, by standardizing the treatments, and
by randomly assigning patients to treatment or no-
treatment groups. A treatment is considered
efficacious to the extent that the average person
receiving the treatment in clinical trials is
demonstrated to be significantly less dysfunctional
than the average person not receiving any treat-
ment (e.g., those on a waiting list for treatment).
empirically supported treatments (ESTs)
Treatments for various psychological conditions
that have been shown through careful empirical
study to be either“well established”or“probably
efficacious.”AlistofESTsisupdatedand
published periodically by the APA’s Division of
Clinical Psychology.
evidence-based treatments (EBTs)Those
interventions or techniques that have produced
significant change in clients and patients in
controlled trials.
evidence-based practice (EBP)Treatments
informed by a number of sources, including
scientific evidence about the intervention, clinical
expertise, and patient needs and preferences.
expert roleThe therapist’s demonstration of
competence (i.e., knowledge and experience).PSYCHOLOGICAL INTERVENTIONS 341