Bulimia nervosa is an eating disorder characterized by binge eating as well as by self-induced vomiting and/or laxative abuse (Mitchell, 1986). Episodes of overeating typically alternate with attempts to diet, although the eating habits of bulimics and their methods of weight control vary (Fairburn et al., 1986). The majority of bulimics have a body weight within the normal range for their height, build, and age, and yet possess intense and prominent concerns about their shape and weight (Fairburn et al., 1986). Individuals with bulimia nervosa are aware that they have an eating problem, and therefore are often eager to receive help. The most common approach to treating bulimia nervosa has been with cognitive-behavioral therapy.
WHAT IS COGNITIVE-BEHAVIORAL THERAPY?
Cognitive-behavioral treatment of bulimia regards individuals' attitudes toward their shape and weight as central to maintaining the disorder. This approach seeks to change individuals' dysfunctional attitudes in order to facilitate recovery. Cognitive-behavioral therapy (CBT) for bulimia is a combination of behavioral techniques and aspects of cognitive therapy. Cognitive therapy (CT) is founded upon the underlying rationale that an individual's affect and behavior are largely determined by the way he/she structures the world (Beck, 1979). The individual's cognitions are based upon attitudes or assumptions that have been developed from previous experiences. Therapeutic techniques of CT treatment are designed to identify, reality-test, and correct distorted conceptualizations and dysfunctional beliefs which underlie the individual's cognitions (Beck, 1979). Therefore CT views an individual's thoughts, beliefs, and values to be interrelated; this combination is then postulated to influence the individual's affect and behavior. Behavioral techniques utilized by CBT are designed not only to change certain behaviors, but also to elicit the individual's cognitions associated with specific behaviors.
CBT treatment typically lasts about 20 weeks and can be divided into three stages (Fairburn et al., 1993). In the first stage, the cognitive view on the maintenance of bulimia is presented, and behavioral techniques are implemented to replace binge eating with more stable eating patterns. In the second stage, additional attempts are made to establish healthy eating habits, and an emphasis is placed upon the elimination of dieting. Cognitive processes (previously outlined) are focused upon extensively in this stage; the therapist and the individual examine his/her thoughts, beliefs, and values which maintain the eating problem. The final stage is concerned with maintaining the gains made in therapy once the treatment has been terminated (Fairburn et al., 1993).
The cognitive view of the maintenance of bulimia nervosa stresses that there is more to an individual's eating problem then just binge eating (and purging). Low self-esteem, extreme concerns about shape and weight, and strict dieting are all implicated in perpetuating the vicious cycle of bulimia (Fairburn et al., 1993). Within the first stage of treatment (weekly sessions 1-8), the following steps characterize the cognitive-behavioral approach: 1) orient the patient (provide information regarding treatment structure and content, likely outcome, treatment style and need for commitment), 2) establish a collaborative therapeutic relationship, 3) take a history of the individual (include eating problems, physical and familial history, prior therapy experience, etc.), 4) outline rationale underlying cognitive-behavioral treatment approach 5) introduce and review monitoring sheets (individual writes down what he/she eats), 6) introduce weekly weighing (individual instructed to weigh self weekly as opposed to daily), 7) introduce and review homework assignments (individual assigned tasks to test cognitions surrounding eating problem), 8) education about weight and eating (body weight, physical consequences of bingeing and purging, ineffectiveness of purging as means of weight control, adverse effects of dieting), 9) advice given regarding eating, vomiting, and purgative use (prescription of a regular eating pattern, use of alternative behaviors, stimulus control and allied measures, advice regarding vomiting, laxatives, and diuretics), 10) joint session with individual's friends or relatives (encourages bringing the problem out into the open, patient explains treatment rationale thereby verifying comprehension of therapeutic principles, friends or relatives through education can subsequently facilitate patient's own efforts at overcoming problem) (Fairburn et al., 1993).
During stage 2 of cognitive-behavioral therapy (weekly sessions 9-16), the following focuses can be expected: 1) continue to review monitoring sheets and homework assignments 2) reduce individual's strong tendency to diet 3) enhance problem solving skills 4) address concerns about shape and weight 5) address other cognitive distortions (Fairburn et al., 1993). The final stage of treatment, stage 3 (sessions 17-19), is composed of three interviews conducted at two weeks intervals. This stage aims to maintain progress once treatment is terminated in order to prevent relapse of the binge/purge cycle (Fairburn et al., 1993). This description of CBT for bulimia nervosa was extracted from a treatment manual designed by leading researchers in the field. The step by step depiction of CBT thereby typifies the approach most likely to be encountered by an individual seeking cognitive-behavioral therapy for bulimia.
CBT has consistently been shown to be applicable and effective in treating
bulimia nervosa (Wilson & Fairburn, 1993). Cognitive-behavioral treatment
has been found to produce significant reductions in the frequency of binge
eating, vomiting, and other compensatory behaviors used by bulimics to
control their weight (Treasure et al., 1994). CBT has been found not only
to produce rapid changes in the eating patterns of individuals with bulimia
nervosa, but its effects have also been found to be well maintained over
time (Waller et al., 1996).
The efficacy of CBT in treating bulimia has been compared in outcome studies with the following interventions: pharmacotherapy, behavior therapy, interpersonal psychotherapy, and supportive-expressive therapy. Antidepressants are the primary pharmacological intervention that is used in the treatment of bulimia. Many have proved effective in decreasing episodes of both bingeing and purging, but the mechanism of action remains unanswered (Hoffman & Halmi, 1993). The responsiveness of the disorder to antidepressant treatment, has continually raised the issue of whether bulimia nervosa is actually a variant of affective disorder (Mitchell et al., 1993). Lithium carbonate, anticonvulsants, opiate antagonists, and serotonin promoting drugs are additional interventions that have been investigated for potential therapeutic effects in treating bulimia nervosa (Hoffman & Halmi, 1993).
Cognitive-behavioral therapy for bulimia has been compared to strict behavioral approaches in terms of treatment efficacy. In a study by Thackwray et al.(1993), 47 women were randomly assigned to a cognitive-behavioral, behavioral, or attention placebo condition. Following treatment for 8 weeks, two assessments were taken for the frequency of binge eating and purging. The first occasion of assessment was at posttreatment (1 week after treatment completion), and the second was at follow-up (6 months after posttreatment assessment). At posttreatment, 92% of individuals who received CBT were found to be abstinent from binge eating-purging, in comparison to 100% of individuals who received behavioral therapy and 69% of the control group. However, at follow- up assessment, 69% in CBT had maintained their abstinence in comparison to 38% in the behavioral group and 15% in the control group.
Cooper & Steere (1995) conducted a similar study comparing the efficacy of cognitive-behavior therapy with a purely behavioral treatment (exposure plus response prevention). These researchers sought to elucidate the role of cognitive factors in the maintenance of bulimia nervosa. Both treatment conditions proved effective in the short term, however at one year follow up, only those who received CBT had not relapsed. These results would appear to support a cognitive model for the maintenance of bulimia. However, this study did not find differences between groups on measures of cognitive disturbance (attitudes toward shape and weight) at posttreatment assessment. Also, the level of cognitive disturbance was not found to be predictive of relapse. In light of these findings, the researchers made the conclusion that the level at which cognitive change takes place may not be accessible by conventional measures of assessment.
Interpersonal psychotherapy (IPT) is another approach with which cognitive-behavioral therapy has been compared to in terms of treatment efficacy. This type of therapy uses techniques derived from psychodynamically oriented therapies, but focuses on the individual's current interpersonal functioning. A study by Jones et al.(1993) compared CBT, behavior therapy (BT), and IPT in terms of changes in the eating behaviors of patients with bulimia nervosa. No differences were found to exist between the three treatments in terms of the time it took to achieve a decrease in the frequency of binge-eating and purging. The researchers proposed that the treatments shared certain "non-specific" properties which were responsible for the beneficial effects seen in eating behaviors, attitudes, level of depression, and self-esteem of bulimic patients.
Fairburn et al.(1993) compared the effects of CBT with IPT, and also compared the effects of CBT with BT. For the individuals who were assigned to BT, over half discontinued the treatment. For those who did remain in the study, very few met criteria for a good outcome when assessed at follow-up. The individuals assigned to CBT and IPT however, made equivalent, substantial, and lasting changes in their symptomatology although IPT took longer to produce its effects. The researchers concluded that bulimia can be successfully treated without focusing upon the individual's eating habits and cognitions concerning shape and weight.
A prospective outcome study was performed by Fairburn et al.(1995) to determine the long-term effects of CBT, BT, and a form of IPT called focal interpersonal psychotherapy. The long term outcome of bulimia nervosa was determined by reassessing 89 individuals who were involved in previous research (mean length of follow-up was 5.8+ 2.0 years). Almost half of these individuals still had an eating disorder: 19% had bulimia nervosa, 3% had anorexia nervosa, and 24% fell into the DSM-IV category of eating disorder not otherwise specified (EDNOS). These researchers determined that individuals who received either CBT or IPT had a better prognosis then those who had received BT, which was found to have short-lived effects.
The final therapy to be discussed in comparison to CBT is supportive-expressive therapy. Garner et al.(1993) investigated the different treatments' efficacy in reducing the frequency of vomiting and binge-eating in 50 women over 18 weeks. Supportive-expressive therapy is a nondirective type of treatment, which emphasizes listening to the individual and helping to identify problems and possible solutions. This therapy is similar to IPT in that both conceptualize the eating symptoms of bulimia to disguise underlying interpersonal problems. In this study both treatments were found to be effective in reducing binge eating, although CBT was found to be superior in reducing frequency of vomiting. In addition, CBT was found to be superior in ameliorating disturbed attitudes toward eating and weight, depression, low self-esteem, and general psychological distress.
The comparative outcome studies described above highlight the efficacy of cognitive-behavioral therapy in the treatment of bulimia nervosa. In all of the studies reviewed, CBT performed as well, or superior to the types of interventions with which it was compared. However, in interpreting the trials comparing pharmacotherapy and psychotherapy, the following points should be kept in mind: 1) in most research studies, small numbers of subjects in similar populations have been employed, thereby making generalizability problematic 2) it is difficult for researchers to be blind to treatment conditions assigned to patients which may bias outcome 3) follow-up periods have generally been a year or less 4) number of binge eating and purging episodes have relied upon subject self-report (Mitchell et al.,1993). Despite such difficulties, however, CBT has been proven not only to be successful in reducing bingeing and purging behaviors, but also to improve psychopathology which presents in individuals with bulimia.
Cognitive-behavioral therapy has been shown to be at least as effective
in treating bulimia, if not more so, then all the treatments with which
it has been compared. However, some individuals fail to benefit from it
while others make only limited gains (Fairburn et al., 1993). Some prognostic
factors have been identified as responsible for this variation in CBT efficacy.
The most potent indicator appears to be the individual's pretreatment level
of self-esteem. Individuals who have very low self-esteem reap the fewest
benefits from CBT (Fairburn et al., 1993). Individuals with personality
disorders also typically fail to respond to CBT interventions, especially
individuals with borderline personality disorder (Coker et al.1993; Rossiter
et al., 1993). Fahy and Russell (1993) identified the following variables
to influence treatment response and outcome in their study of 39 patients
with bulimia nervosa: personality disorder, pretreatment symptom severity,
and longer duration of illness. In a study by Blouin et al. (1995), CBT
program completers could be differentiated from CBT program dropouts by
their fewer difficulties in trusting and relating to others. Gleaves and
Eberenz (1994) conducted a study in which they assessed the history of
sexual abuse in bulimic women who failed to engage in CBT treatment (reviewed
a total of 464 women). Approximately 71% of the women who failed to respond
to treatment reported a history of sexual abuse. The researchers propose
that treatment should address both the eating disorder and the posttraumatic
condition, if symptoms and histories of the trauma arise in individuals
who fail to respond to CBT. Therefore, although CBT has consistently and
convincingly been found to be effective in treating bulimia nervosa, there
are certain circumstances in which outcome efficacy is limited.
Bulimia nervosa can have disastrous consequences for an individual upon
physical, emotional, psychological, and social levels. Fortunately, most
bulimics realize that they have a problem which needs to be addressed,
and often agree to engage in some type of treatment intervention. Cognitive-behavioral
therapy (CBT) is the type of treatment most often utlilized when dealing
with bulimia nervosa. The goal of CBT is to change an individual's faulty
cognitions surrounding his/her shape and weight. Therapists who practice
this method accomplish the goal of treatment through a combination of behavioral
techniques and aspects of cognitive therapy. CBT has proved to be effective
when evaluated in isolation, and also when judged in comparison to alternative
interventions. Theoretical issues have been raised as to the limitations
of outcome studies, yet the fact still remains that CBT is a very effective
approach when dealing with bulimia nervosa. Despite the efficacy of CBT,
however, certain circumstances do prevent an individual from responding
optimally to treatment. This limitation in therapeutic effectiveness, however,
is found in any type of treatment when it is faced with challenging patient
characteristics. Therefore, CBT has been illustrated in numerous ways,
by countless individuals, to be an effective intervention for targeting
and treating the symptoms of bulimic individuals.
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