Dialectical Behavior Therapy for Binge Eating and Bulimia (3 page)

CHAPTER
1

Binge-Eating Disorder
and
Bulimia
Nervosa
Why Dialectical Behavior Therapy?

T
his chapter explores the many problems faced by people with binge-eating
disorder (BED) and bulimia nervosa (BN), focusing on key features of these disorders, as well as on their associated impairments to one’s psychological, physi—
cal, and social functioning. Although treatment with current leading therapies,
such as cognitive-behavioral therapy (CBT), interpersonal psychotherapy (IPT),
and behavioral weight loss therapy (BWL) offers signifcant improvement, the fact
that a sizeable number of clients remain symptomatic after these treatments has
prompted the development of other therapy models. We present support for one
such model, an affect regulation model of binge eating and purging. This includes
outlining the rationale for adapting dialectical behavior therapy (DBT), originally
developed to target affect dysregulation among individuals with borderline personality disorder, to treat disordered eating behaviors. We conclude with a summary
of the available research evidence for the effcacy of DBT for BED and BN.

OVERVIEW

BED and BN, the two eating disorders for which the treatment described in this
book has been researched in randomized trials, are both typifed by binge eating.
Two components determine whether an eating episode is a binge: the quantity of
food eaten and the presence of an accompanying sense of lack of control (American
Psychiatric Association, 2000). In other words, the amount of food consumed over a
discrete time period (e.g., 2 hours) should be unusually large compared with what
most people would eat in the same time period under similar circumstances. In
addition, during the episode, a lack of control is felt, as if one could not stop eating
or control what or how much is eaten. BN is distinguished from BED by the use

DIALECTICAL BEHAVIOR THERAPY FOR BINGE EATING AND BULIMIA

of compensatory behaviors (e.g., vomiting, extreme dietary restriction, laxative or
diuretic misuse, overexercise) in response to binge eating.

BINGE-EATING DISORDER

BED is currently listed in the appendix of the text revision of the fourth edition of
the Diagnostic and Statistical Manual of Mental Disorders
(DSM-IV-TR; American
Psychiatric Association, 2000) as a research diagnosis requiring further study.
The proposed criteria for the diagnosis include the occurrence of binge eating
approximately 2 days per week for a minimum period of 6 months in the absence
of compensatory behaviors. Other associated features include eating much more
quickly than normal, eating to the point of physical discomfort, eating despite lack
of physical hunger, eating alone due to embarrassment about one’s amount of food
intake, and feeling disgust, depression, or guilt after binge eating.

About 2–5% of the general population suffers from BED (Bruce & Agras, 1992;
Fairburn, Cooper, Doll, Norman, & O’Connor, 2000; Spitzer et al., 1992, 1993). Its
prevalence is even higher among certain groups of individuals, such as those seek—
ing treatment for weight control (20–40%; Spitzer et al., 1992, 1993; Brody, Walsh,
& Devlin, 1994). Of those undergoing bariatric surgery, up to 49% meet criteria
for BED (see reviews by de Zwaan et al., 2003; Niego, Kofman, Weiss, & Geliebter,
2007). And among members of Overeaters Anonymous, rates of those suffering
from BED have been estimated to reach 71% (Spitzer et al., 1992).

BED is more common in women. However, a notable number of men also suffer
with this disorder. The ratio of males to females is 2:3 among overweight individuals with BED and approaches 1:1 in community samples (Spitzer et al., 1992).

People diagnosed with BED typically describe a lifetime struggle with both
their binge-eating symptoms and issues of weight control. By midadolescence or
early adulthood, the onset of binge eating, dieting, and overweight has usually
occurred (Spurrell, Wilfey, Tanofsky, & Brownell, 1997), and, unfortunately,
these often become ongoing concerns. In one large study of individuals with BED,
three-quarters reported having spent more than half their adult lives on diets,
and about half had gained and lost at least 20 pounds fve times or more (Spitzer
et al., 1993).

Although some individuals with BED have normal weight, people meeting criteria for BED are more likely to be overweight or obese (e.g., Bruce & Agras, 1992).
Indeed, a number of studies (Bruce & Agras, 1992; Spitzer et al., 1993; Telch,
Agras, & Rossiter, 1988) have shown a positive association between the frequency
of binge eating and the degree of obesity as measured by body mass index (BMI;
kg/m2). Despite this overlap between binge eating and obesity, important differences exist between people with BED and weight-matched individuals (i.e., those
who are equally overweight) who do not meet BED criteria. These differences span
multiple domains, including psychiatric and eating-disorder-specifc disturbances,
social and work-related impairments, and physical consequences—as discussed in
the following sections.

Adding to the serious diffculties faced by clients with BED, carrying the diagnosis of BED predicts a worsened outcome in response to weight loss treatment.
For example, overweight participants with BED enrolled in a weight loss clinic

Why Dialectical Behavior Therapy?

attained only 55% of the weight loss achieved by their fellow participants without
BED (Pagoto et al., 2007). A review by Niego and colleagues (2007) of bariatric surgery patients showed that those with signifcant binge-eating histories were more
likely to have a poorer outcome—including greater likelihood of suffering from disordered eating after surgery (Hsu, Betancourt, & Sullivan, 1996; Hsu, Sullivan,
& Benotti, 1997), smaller loss of initial excess weight (Sallet et al., 2007), higher
levels of weight regain (Hsu et al., 1996), and greater requirements for postopera—
tive adjustments (Busetto et al., 2005).

Psychiatric and Eating-Disorder-Specifc Symptomatology in BED

Carrying a diagnosis of BED is associated with higher levels of psychiatric symptoms compared with weight-matched controls without BED. In a study that exam—
ined non-treatment-seeking individuals, the rates of lifetime major depression
(49%), as well as of any Axis I diagnosis (59%), were about twice those found in
overweight/obese controls without BED (28% and 37%, respectively; Telch & Stice,
1998). Another large study found that overweight individuals with BED, as compared with overweight individuals without BED, were more likely to have a history
of alcohol abuse (15% versus 1.7%) or drug abuse (13% versus 4%; Spitzer et al.,
1993).

In terms of personality disorders, the likelihood of being diagnosed with any
Axis II disorder was found to be four times higher (20%) in those with BED than
in overweight/obese controls (5%; Telch & Stice, 1998). Both Cluster B (e.g., border—
line personality disorder) and Cluster C (e.g., avoidant personality disorder, obses—
sive–compulsive personality disorder) were signifcantly more prevalent (Specker
et al., 1994).

Of note, research has also shown that the degree of co-occurring psycholog—
ical disorders is related to binge-eating severity rather than to degree of overweight (Picot & Lilenfeld, 2003; Telch & Agras, 1994; Yanovski, Nelson, Dubbert,
& Spitzer, 1993). Indeed, rates of co-occurring psychiatric disorders among obese
individuals without BED are similar to rates in a nonpatient community sample
(Spitzer et al., 1993; Telch & Stice, 1998).

In addition to increased rates of psychiatric symptoms, those with BED also
demonstrate higher levels of eating-disorder-specifc pathology. For example, individuals with BED report greater overconcern about weight and shape (Eldredge &
Agras, 1996; Spitzer et al., 1993), more fears of weight gain, a higher preoccupa—
tion with food and weight, and greater body dissatisfaction (e.g., Wilson, Nonas, &
Rosenblum, 1993). Importantly, these eating-disorder-specifc symptoms, such as
overconcern with weight and shape, have been shown to be independent of actual
body weight (e.g., Eldredge & Agras, 1996).

Social and Occupational Impairment in BED

People with BED are also more likely to show impaired social and occupational
functioning. Spitzer and colleagues (Spitzer et al., 1993) found that 65.1% of participants with BED, compared with 28.8% of weight-matched controls, reported
impaired interpersonal relationships due to distress about their eating and weight.
Similarly, reports of work impairment due to eating and weight-related distress

DIALECTICAL BEHAVIOR THERAPY FOR BINGE EATING AND BULIMIA

were more than double in those with BED (44.5%) compared with weight-matched
individuals without the disorder (17.3%; Spitzer et al., 1993).

Other investigators examining the impact of BED on quality of life found signifcantly higher ratings of overall distress among obese individuals with BED compared with obese individuals without the disorder (Rieger, Wilfey, Stein, Marino,
& Crow, 2005). When asked to assess the effects of being overweight on specifc
domains of quality of life, those with BED reported signifcantly more impairment
in the psychosocial domains of work (e.g., receiving appropriate raises), public
activities (e.g., worrying about ftting into seats in public spaces), sexual life (e.g.,
sexual desire), and self-esteem (Rieger et al., 2005). Because the participants with
and without BED were comparable in terms of degree of overweight, these fndings
could not be attributed to elevated levels of obesity (Rieger et al., 2005).

Physiological Consequences of BED

As noted, people with BED are more likely to be overweight or obese than individuals without BED. Also, the greater the severity of binge eating—in terms of
its frequency and size—the higher the degree of overweight, as measured by the
BMI (Bruce & Agras, 1992; Picot & Lilenfeld, 2003; Telch et al., 1988). (Normal
is defned as a BMI between 18.5 and 24.9, overweight as a BMI between 25 and
29.9, and obesity as a BMI of 30 or greater [National Heart, Lung, and Blood Institute and the National Institutes of Health, 1998].) In a community sample of 455
women, for example, women who met full criteria for BED had higher average body
weights (BMI = 30.24) than those who binged less than two times per week (BMI
= 26.21), and the BMIs of this latter group were higher than among those who did
not binge at all (BMI = 22.85; Bruce & Agras, 1992).

Not surprisingly given the overlap between BED and obesity, individuals with
this disorder are more likely to suffer from the signifcant medical problems associated with obesity itself (e.g., hypertension, stroke, heart disease, sleep apnea,
colon cancer, breast cancer; National Heart, Lung, and Blood Institute, 1998; Pi—
Sunyer, 2002). This association highlights the prominent public health implica—
tions of BED. In some instances, the presence of binge eating appears to confer
additional medical consequences above and beyond those accounted for by obesity
alone. For example, rates of Type II diabetes were 14% among those binge eating
at least two times per week compared with 4% in controls matched for BMI and age
(Kenardy, Mensch, Bowen, & Pearson, 1994). In addition, a signifcant relationship was found between glycemic control (as measured by HbA1c) and binge eating
among Type II diabetics with BED—a relationship that was independent of weight
(Kenardy, Mensch, Bowen, & Dalton, 2001). Further evidence of the serious physi—
cal consequences associated with a diagnosis of BED is the overall health status
of participants with BED, which is signifcantly lower than U.S. norms and even
lower than that of obese weight-matched controls (Hsu et al., 2002).

Emotions, Affect Regulation, and BED

Research evidence highlights the role emotions (particularly negative emotions)
and affect regulation play in binge eating. For example, the most frequently cited

Why Dialectical Behavior Therapy?

precipitants of binge eating are stress and negative mood (Polivy & Herman, 1993).
Furthermore, overweight binge eaters report higher urges to binge in response to
negative emotions than those who do not binge eat, irrespective of level of overweight (Eldredge & Agras, 1996). In a study examining which of six emotions
are most associated with triggering binge eating, anxiety was the most frequently
cited, followed by sadness, loneliness, tiredness, anger, and happiness (Masheb &
Grilo, 2006).