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A COMPARISON BETWEEN COGNITIVE-BEHAVIORAL THERAPY AND EXPOSURE
WITH RESPONSE PREVENTION IN THE TREATMENT OF BULIMIA NERVOSA
INTRODUCTION
Bulimia
nervosa is an eating disorder with psychological, physiological, developmental,
and cultural components. The disorder is
commonly characterized by binge eating followed by inappropriate compensatory
behaviors, such as self-induced vomiting, excessive exercise, fasting, and the
misuse of diuretics, laxatives or enemas.
Patients properly diagnosed with bulimia nervosa endure many
psychological and physiological problems.
In order to alleviate these problems for the patient, usually some type
of intervention is required. Considering
the financial costs to the patient who seeks treatment, it is important to identify
effective and efficient treatment programs.
Due to the wide variety of individual patient differences, it would be
unwise to proclaim one treatment method as the universal cure for bulimia
nervosa. However, identifying what
methods work under particular conditions may help therapists tailor an
individualized treatment program after a careful assessment of the client. Having this knowledge would potentially save
both the client and the therapist a lot of time and frustration; not to
mention, the patient would be on the path to recovery sooner. Kaye et al (1999) stress the importance of
making progress towards the understanding and treatment of anorexia and bulimia
nervosa, in order to generate more specific and effective psychotherapies and
pharmacologic interventions.
In this paper, I will present my analysis of two methods
used to treat bulimia nervosa. The first
method is cognitive-behavioral therapy for bulimia nervosa; this method is
quite popular among psychologists who specialize in the treatment of eating
disorders. The second method is called
exposure with response prevention; this method is the product of behavior
therapy and is used less frequently than cognitive-behavior therapy. Both methods have been proven to be
significantly effective in reducing the symptoms of bulimia nervosa. Although immediate reduction of bulimic
symptoms is beneficial to the patient, it is not indicative of recovery. For this reason, my analysis will consider
the long-term outcome effects for each treatment method. My findings will influence which method I
will recommend for the treatment of bulimia nervosa.
COGNITIVE-BEHAVIORAL THERAPY: MOST POPULAR
METHOD FOR THE TREATMENT OF BULIMIA NERVOSA
What is Cognitive-Behavioral Therapy
In 1981, a researcher named Fairburn conducted the first
study applying cognitive-behavioral therapy to the treatment of bulimia
nervosa. In a recently published report
by D. L. Spangler (1999), CBT is touted as “a well-developed, theoretically
grounded treatment for bulimia nervosa with the strongest empirical support for
its efficacy of any form of treatment for bulimia nervosa.” Today cognitive-behavioral therapy (CBT) is a
form of therapy commonly used to treat patients with bulimia nervosa (BN).
More
specifically, CBT is normally structured as a series of interventions that
addresses the cognitive aspects and the behavioral components of a particular
disorder. The cognitive-behavioral
approach is based on a theoretical view, which “holds the patients’ beliefs
about weight, shape and eating as central to the maintenance of bulimia
nervosa…effective treatment, therefore, depends on altering patients’
assumptions about he importance of shape and weight” (Cooper & Steere,
1995). Some of the other cognitive
aspects that therapists should focus on are: preoccupation with the body and
food, perfectionism, low self-esteem, etc. (McGilley & Pryor, 1998). Therapists should also focus on the
behavioral components of BN such as: disturbed eating habits, binge eating,
purging, dieting, and ritualistic exercise.
In the case of BN, the initial goal of CBT is “to restore control over
dietary intake” (McGilley & Pryor, 1998).
The logical explanation for this goal is that caloric restriction and
dieting efforts tend to make patients more susceptible to binging if provoked
by food cues. By avoiding caloric
restriction and dieting efforts, the urge to binge decreases for patients,
especially when patients are eating a well-balanced, normal-sized diet. Patients are typically directed to monitor
and record the thoughts, feelings, and circumstances surrounding binge-purge
episodes in a journal, which may then be analyzed by the therapist in order to
provide the patient with constructive feedback.
Most forms of CBT recommend cessation of dieting efforts and adherence
to a normal diet. CBT also targets the
patient’s tendency to link body weight with self-esteem.
Is CBT effective in the treatment of Bulimia
Nervosa?
McGilley
and Pryor (1998) warn, “although cognitive-behavioral therapy is the first-line
of treatment of choice for bulimia nervosa, its effectiveness is limited.” McGilley and Pryor’s study (1998) reports
that approximately 50 percent of patients who receive CBT stop binge eating and
purging, while the remaining 50 percent show only partial improvement. The latter 50 percent of patients who only
show partial improvement may be suffering from a comorbid illness, which may
effect the outcome of CBT. More
importantly, both researchers and patients need to keep in mind that BN is a
difficult disorder to treatment. In
fact, the majority of patients experience post-treatment relapse(s) regardless
of the type of treatment method used.
For this reason, both researchers and patients need to work together in
order to construct more effective treatment approaches, guidelines, and
interventions.
The
majority of research evidence on CBT supports the treatment program’s
effectiveness in managing the symptoms of BN.
However, not all of the findings can or should be taken as fact. Bulik et al (1998) conducted a study that
evaluated the role of exposure with response prevention (ERP) in the
cognitive-behavioral therapy treatment for BN.
Bulik et al (1998) reported CBT as “a highly effective treatment for
BN;” whereas, exposure with response prevention “did not appear to offer any
significant additive benefits that are proportional to the amount of effort
required to implement the treatment.” It
is important to note that traditional CBT was administered before ERP
treatment; hence, patients initially improved and then plateaued out when ERP
was administered. Perhaps, if ERP was
administered as the primary treatment with traditional CBT to follow as the
secondary treatment, the conclusions drawn in the Bulik et al (1998) study
would have been exactly the opposite of what was actually reported. That is, if ERP was administer first, then
the patient’s improvement would have been attributed to ERP rather than
CBT. Just some food for thought (no pun
intended).
A
study conducted by Steel et al (1995) reports that “while treatment has largely
been effective at reducing binge purge frequencies, it does not result in the
elimination of the presenting problem for a significant proportion of
participants.” So although the frequency
of bulimic symptoms is reduced with implementation of CBT, this reduction does
not constitute a recovery according to some therapists. As a side note, the controversy seems to be
over what constitutes or what defines a recovery for a patient diagnosed with
bulimia nervosa. Is it reduced
symptomology of bulimia nervosa, complete elimination of symptoms with or
without an occasional relapse? Is it the resumption of eating regular meals
without dietary restrictions? Is CBT too
short? How long should treatment continue?
Should there be “maintenance” sessions?
Should CBT be combined with pharmological therapy and if so for how
long? These are the questions that
perplex psychologists researching and treating eating disorders, such as
bulimia nervosa. The fact that these
questions remain unanswered justifies why interventions are greatly
needed. Furthermore, since only 50
percent of the patients treated with CBT improve and fully recover, it becomes
increasingly important to be able to accurately predict who will benefit from
CBT and who will not benefit.
What are the prognostic indicators for the
outcome of CBT?
Leung
et al (2000) reports “individuals who benefit less from CBT will be those who
have more pathological core beliefs (unconditional beliefs, unrelated to food,
shape, and weight).” Leung et al (2000)
suggest that CBT as applied in the treatment of BN may not work for some of the
patients because the cognitive focus is too narrow. Granted, bulimic symptoms are generally
“precipitated and maintained by a set of maladaptive thinking patterns
regarding body weight, size, and shape;” however, other factors such as
maladaptive personalities, schemas, and other cognitive representations need to
be considered when designing a patient’s treatment program (Leung et al, 2000).
That is, patients with BN express a more general dysfunctional thinking style
than just maladaptive beliefs regarding food, weight, and shape. When placed in a group CBT condition, most
bulimics show signs of improvement; however, those with more pathological core
beliefs tend to have poorer outcomes after completing the prescribed treatment
program (Leung et al, 2000). The results
of this study should be considered with caution. The sample size (N = 20) is small, which
tends to reduce the reliability of the results.
In addition, the patients received group CBT as opposed to individual
CBT. Perhaps the patients with “more
pathological core beliefs” and who were identified as having poorer treatment
outcomes would have done better had they received individual CBT and not group
CBT.
In
the common pursuit of establishing appropriate treatment guidelines and
increasing the efficacy of clinical intervention, Francisco J. Vaz report
(1998) also provides some prognostic indicators of who will and will not do
well in various treatment programs. As
do many of his colleagues, Vaz reports that while the majority of bulimics show
a fair initial response to a wide variety of treatments, most tend to relapse
despite the method of treatment used (1998).
More specifically, Vaz mentions several prognostic indicators linked to
poorer outcome after treatment for the management of BN, including: intensity
of vomiting, binge frequency, history of disorders, distorted body image,
inability to maintain stable body weight, age of onset, duration of the
illness, comorbidity with depression, substance abuse, low self-esteem,
impulsiveness/ineffectiveness characteristics, etc (1998). Vaz suggests that treatment should be intensified
for individuals who show any of the aforementioned indicators (1998). This intensification is especially important
for patients with comorbid disorders, since comorbidity tends to complicate the
treatment of BN. Nevertheless, I would
think that it is important to treat all patients who receive the diagnosis of
BN with the same level of intensity. All
patients who are suffering from BN are presenting symptoms that indicate real
problems, for this reason these patients should be given the best care
available to ensure the best chances for recovery.
EXPOSURE WITH RESPONSE
PREVENTION: AN ALTERNATIVE TREATMENT FOR BULIMIA NERVOSA
What is Exposure with Response Prevention?
Exposure with response prevention (ERP) is an alternative
treatment approach designed to treat patients with bulimia nervosa or anorexia
nervosa with the purging sub-type. ERP
involves “planned, sustained, and repetitive exposures” to forbidden foods
followed by prevention measures, which prevent the patient from binging and/or
purging (Kennedy et al, 1995). There are
two variations of ERP treatment. One
version is called exposure with response prevention of vomiting (ERP-V). This treatment method involves exposing the
patient to forbidden foods, and allowing the patient to eat as much of the food
as desired. The patient is then
monitored and purging efforts are prevented.
Patient monitoring ceases when the patients’ urge to vomit
subsides. The other version of ERP is
called exposure with response prevention of binging (ERP-B). This particular treatment method involves
exposing the patient to forbidden foods, and allowing the patient to touch,
smell, lick, taste, but not binge on the food items. The patient is monitored and binging is
prevented until the urge to binge has subsided.
Studies conducted by Schmidt and Marks (1989) and Rosen and Leitenberg
(1982) support the effectiveness of ERP-B.
ERP treatment programs strongly resemble the behavior methods used to
desensitize people to personally distressing stimuli. In fact, ERP may be classified best as a form
of behavioral therapy.
Popularized in the 1960s, behavioral therapy focuses “only
on aspects of human behavior that can be quantified; aspects of human behavior
that are inferential (e.g., unconscious conflicts) cannot be reliably measured
due to the lack of tangibility” (Sloan & Mizes, 1999). The key principle of behavior therapy is that
behavior is a function of its consequences.
If a behavior is reinforced, then the behavior is more likely to be
repeated. If a behavior is punished,
then the patient is less likely to repeat the behavior.
Applying
this principle to treatment methods for eating disorders, one would conclude
that if a person binges and then is able to reduce the feelings of anxiety
about binging, and the fears of gaining weight by purging, then the purging
behaviors will be reinforced. Moreover,
Rosen and Leitenberg suggest, “binging in bulimia nervosa is more a consequence
of vomiting than vomiting is a consequence of binging” (1982). That is, once a person has learned how to reduce
anxiety about gaining weight via purging, the person will be more likely to
binge because they can purge. The goal
of ERP, especially ERP-V, is to un-teach the self-destructive behaviors
associated with BN. Many behavior
therapists believe that maladaptive behavior is more effectively changed “by
doing, not talking, …by practicing new behaviors, as well as exposure to
critical cues;” furthermore, “merely talking and gaining insight about
behaviors does not necessarily result in change” (Sloan & Mizes,
1999). Although behavior therapists
strongly advocate action over cognitive exploration, many researchers agree
that the cognitive aspects of human behavior are considered important in
understanding psychopathology and its treatment (Sloan & Mizes, 1999).
How effective is ERP is treating Bulimia Nervosa?
As
reported in Bulik et al (1998), a one year post treatment follow-up on patients
treated with ERP-B indicated that treatment programs were most effective when
the treatment goals include abstinence from binging and restricting, and
decreasing the urge to binge in response to high risk cues. In addition, Kennedy et al (1995), patients
treated with ERP-B showed reductions in the urge to binge/vomit, anxiety
levels, tension, guilt, depression, and lack of control. These reductions provide support for the
efficacy of ERP treatment methods for BN.
However, Kennedy et al (1995) also reported no change in the patients’
feelings of fatness either during the sessions or after treatment. This last observation indicates that perhaps
behavior therapy alone is not sufficient in curing BN. Considering that the
risk of relapse might increase if feelings of fatness persist beyond treatment,
a more cognitive or psychotherapeutic approach might be implemented for a more
favorable outcome.
Although
the data on ERP does indicate that the treatment provides some benefits to the
patient, ERP is not the preferred method of treatment for BN. ERP is both expensive and logistically
complicated (Bulik et al, 1998). The
treatment setting is unrealistic and reactivity effects compromise the true
results of the treatment (Kennedy et al, 1995).
Recall that in ERP treatment conditions, researchers monitor the
subjects during and after exposure.
Bulik et al (1998) conclude that ERP therapy for BN fails to offer “any
significant additive benefits proportional to the amount of effort required to
implement the treatment.”
Furthermore,
a study conducted by Cooper and Steere (1995) suggests that ERP therapy does
contain cognitive elements, since every exposure session also included
cognitive restructuring. Likewise,
Cooper and Steere point out that most cognitive behavioral therapies contain
some elements of ERP therapy (1995).
Since these therapies tend to coexist, Cooper & Steere’s study
(1995) isolated the two therapies to learn more about each treatment program’s
effectiveness. The results suggest that
pure CBT was more effective than pre ERP therapy (Cooper & Steere, 1995). In fact, Cooper and Steere report “virtually
all the patients in the ERP group deteriorated after treatment and virtually
none of the patients in the CBT group did” (1995).
What
are the predictors of outcome for ERP treatment?
The
predictors of poor outcome after a patient receives ERP treatment for BN
include: history of obesity, presence of major depression, high scores on the
Eating Disorders Inventory, pre-treatment global functioning, post-treatment
binging, food restriction, etc. (Bulik et al, 1998). The best predictor for favorable outcome for
patients receiving ERP treatment for BN was a high level of self-directedness
(Bulik et al, 1998). These predictors,
especially the level of self-directedness, suggest that a more cognitive
approach to treating BN may yield more favorable results than a strictly
behavioral treatment approach.
CONCLUSIONS
Given the information presented in this paper, I would
recommend using cognitive-behavioral therapy rather than exposure with response
prevention therapy for the treatment of bulimia nervosa. Granted, more research is needed to improve
guidelines used for the assessment and treatment of eating disorders. This new information will help psychologists
and psychotherapists design new treatment programs to maximize the outcome of
clinical intervention. I believe this
paper has demonstrated that psychotherapists should not try to simplify a
disorder for the purpose of a quick and easy treatment program. People are complicated beings; people
suffering from eating disorders are even more complicated. Consequently, the care of patients diagnosed
with eating disorders should draw upon “a comprehensive array of approaches”
and treatment programs rather than limiting the potential benefits of therapy
through adherence to a solitary treatment approach (Practice guideline for,
2000).
REFERENCES
Bulik, C. M.,
Sullivan, P. F., Carter, F. A., McIntosh, V. V., & Joyce, P. R.
(1998).
Predictors of 1-year treatment outcome in bulimia nervosa. Comprehensive Psychiatry, 39, 206-214.
Bulik, C. M., Sullivan, P. F., Carter, F. A.,
McIntosh, V. V., & Joyce, P. R. (1998). The
role of exposure with response prevention in the
cognitive-behavioral therapy for bulimia nervosa. Psychological Medicine, 28,
611-623.
Cooper, P. J., & Steere, J. (1995). A
comparison of two psychological treatments for
bulimia nervosa: Implications for models of maintenance. Behavioral Research and Therapy, 33, 875-885.
Kaye, W., Strober,
M., Stein, D., & Gendall, K. (1999). New directions in treatment
Research of anorexia and bulimia
nervosa. Biological Psychiatry, 45,
1285-1292.
Kennedy, S. H.,
Katz, R., Neitzert, C. S., Ralevski, E., & Mendlowitz, S. (1995).
Exposure with response prevention treatment of anorexia
nervosa-bulimic subtype and bulimia nervosa.
Behavioral Research and Therapy, 33, 685-689.
Leung, N., Waller, G., & Thomas, G.
(2000). Outcome of group cognitive-behavior
therapy for bulimia nervosa: The role of core beliefs. Behavior Research and Therapy, 38, 145-156.
McGilley, B. M.,
& Pryor, T. L. (1998). Assessment
and treatment of bulimia nervosa.
American Family Physician, 57, 2743-2750.
Practice guideline
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American Journal of
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Rosen, J. C., & Leitenberg, H.
(1982). Bulimia nervosa: Treatment with
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Schmidt, U., & Marks, I. M. (1989). Exposure plus prevention of bingeing vs.
exposure
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Sloan, D. M., & Mizes, J. S. (1999).
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Clinical Psychology Review, 19, 255-274.
Spangler, D. L.
(1999). Cognitive-behavioral therapy for
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Steel, Z. P., Farag, P. A., &
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Walsh, B. T., &
Devlin, M. J. (1998). Eating disorders:
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