Weight loss, cognitive-behavioral, and desipramine treatments in binge eating disorder. An additive design

13EHAVIOR THERAPY 25, 225-238, 1994

Weight Loss, Cognitive-Behavioral, and Desipramine Treatments in Binge Eating Disorder. An Additive Design

W . STEWART AORAS

CHRISTY F. TELCH

BRUCE ARNOW

KATHLEEN ELDREDQE

DENISE E. WILFLEY

SUSAN D. RA~BURN

JUDITH HENDERSON

MARGARET MARNELL

Stanford University School of Medicine

The aim of this study was to compare the effects of weight loss treatment, cognitive- behavioral treatment, and desipramine on binge eating and weight in a three group additive design involving 108 overweight participants with binge eating disorder. Sub- jects were allocated at random to either 9-months weight-loss-oniy treatment; 3-months of cognitive-behavioral treatment followed by weight loss treatment for 6-months; or the combination treatment with desipramine added for the last 6-months. After 3-months of treatment, those receiving cognitive-behavioral therapy had reduced binge eating significantly more than participants receiving weight loss therapy only, and the weight loss only group had lost significantly more weight than those in the cognitive- behavioral groups. The addition of medication did not lead to greater reductions in the frequency of binge eating. Hence, there was no evidence that either cngnitive- behavioral therapy or desipramine added to the effectiveness of weight loss therapy. However, those receiving medication lost significantly more weight than the comparable group without medication at follow-up. Abstinence from binge eating was associated with significantly greater weight losses. Overall, however, the achieved weight losses were small and the abstinence rates low. Moreover, there were no differences between the three groups either at the end of treatment or at foUow-up. Suggestions for further research aimed at improving the therapeutic results for this difficult clinical problem are discussed.

This research was supported in part by MH 38637 from the National Institutes of Health. Requests for reprints should be sent to W. Stewart Agras, M.D., Department of Psychiatry, Stan- ford University School of Medicine, 101 Quarry Road, Room 1332, Stanford, CA 94305-5544.

225 0005-7894/94/0225-023851.00/0 Copyright 1994 by Association for Advancement of Behavior Therapy

All rights of reproduction in any form reserved.

226 AGRAS ET AL.

The recent renewal of interest in the subgroup of individuals with eating disorders who binge eat but do not regularly purge, now referred to as binge eating disorder (BED) (Walsh, 1992), has focused attention on the needs of these individuals for treatment. Binge eating disorder has a prevalence of 1.8°70 in the general population of females (Bruce & Agras, 1992), but has a much higher prevalence among the obese, increasing in frequency with increasing body mass index (BMI) (Telch, Agras, & Rossiter, 1988). There is also evidence that BED is associated with a high prevalence of comorbid psychopathology, including major depression, panic disorder, and borderline and avoidant personality disorders (Kolotkin, Revis, Kirkley, & Janick, 1987; Marcus, Wing, Ewing, Kern, Gooding, & McDermott, 1990; Yanovski, Nelson, Dubbert, & Spitzer, 1992).

Binge eating disorder appears to be related to bulimia nervosa (BN), with, for example, both groups of patients experiencing restrained eating alternating with binge eating, although the degree of restraint in BED is less than in BN (McCann, Rossiter, King, & Agras, 1990; Rossiter, Agras, Telch, & Bruce, 1992). Hence, it seemed likely that treatments effective in reducing binge eating in BN would also be effective in BED. The first test of this proposition was a randomized double-blind study of the use of desipramine in binge eating disorder (McCann & Agras, 1990). Those receiving desipramine in this 12-week study decreased their binge eating significantly more than those receiving placebo, with 60% abstinent at the end of treatment, although there was a tendency to relapse once desipramine was withdrawn. There was no significant difference between the groups in weight loss, although those receiving desipramine lost 2.3 kg more than those receiving placebo. The second study examined the effectiveness of group cognitive-behavioral treatment with a waiting list control (Telch, Agras, Rossiter, Wilfley, & Kenardy, 1990). Cognitive- behavioral therapy was more effective than no treatment in reducing binge eating, with 79070 of treated participants abstinent by the end of treatment, although there was a tendency to relapse following treatment. Patients treated with cognitive-behavioral therapy gained a small amount of weight during treatment. The effects of cognitive-behavioral therapy were essentially con- firmed in a recent uncontrolled study (Smith, Marcus, & Kaye, 1992) with a 50% abstinence rate. Participants lost 1.1 kg during the course of treatment. Finally, based on a study by Falrburn et al. (1991) in which interpersonal therapy was found to be as effective as cognitive-behavioral therapy for bulimia nervosa, a similar comparison was made in binge eating disorder (Wilfley et al., 1993). As was the case in bulimia nervosa, cognitive-behavioral and interpersonal therapies were equivalent in their effects on binge eating, and both were superior to a waiting list control group. However, participants gained 2 kg over the course of treatment with no significant difference between groups. These studies suggest that therapies demonstrated effective in the treatment of bulimia nervosa are also effective in the treatment of binge eating disorder.

Although CBT, IPT, and desipramine, are helpful in reducing binge eating, their effect on weight appears negligible. Smith et al. (1992) noted, however, that patients who decreased their binge eating by at least 93070 lost significantly more weight than the remaining participants (2.4 kg versus a small gain). This

TREATMENT OF BINOE EATING DISORDER 227

suggests that it may be necessary to first treat binge eating and then attempt a weight loss program in order to deal with both binge eating and overweight.

Based on these considerations, the present study examined the potential efficacy of a sequential treatment for binge eating and weight loss among obese binge eaters by comparing in a randomized design three experimental groups: (1) Weight loss therapy extending for 9 months (WL); (2) Cognitive-behavioral therapy for binge eating for 3 months followed by weight loss therapy for 6 months (CBT/WL); and (3) Cognitive-behavioral therapy for 3 months followed by weight loss therapy combined with desipramine treatment for 6 months (CBT/WL-D). In the latter group, desipramine could have been added in the last 3 months of treatment. We chose, however, to give desipmmine for 6 months, because there is tentative evidence in the treatment of bulimia ner- rosa that relapse is less frequent in patients treated with antidepressants for 6 months than for a shorter time (Agras et al., 1992; Agras et al., in press; Mitchell et al., 1990).

Desipramine was chosen for this study due to its demonstrated efficacy in reducing binge eating in both bulimia nervosa (Pope & Hudson, 1986) and binge eating disorder (McCann et al., 1990), because we were primarily interested in a medication that would enhance and maintain the reductions in binge eating consequent upon the use of cognitive-behavioral therapy. Because desipramine reduces hunger and overeating (McCann et al., 1990), weight loss may also be enhanced by such treatment. Other medications might have been considered. For example, fluoxetine is effective in reducing binge eating in bulimia nervosa (Fluoxetine Bulimia Nervosa Collaborative Study Group, 1992), and is also more effective in promoting weight loss in the obese binge- eater than the non-binge eater, although there was no effect on binge eating over and above that of weight loss therapy (Marcus, Wing, Ewing, Kern, Gooding, McDermott et al., 1990). The appetite suppressants have recently been shown effective in promoting weight loss over the long-term (Weintraub, 1992), however, such medication has uncertain effects on binge eating (Rus- sell, Checkley, Feldman, & Eisler, 1988). Hence, we chose to use desipramine in this study.

Method

Subjects One hundred and eight female subjects meeting the proposed criteria for

BED (Walsh, 1992) participated in this study. These criteria are as follows: A. Recurrent episodes of binge eating. An episode of binge eating is charac-

terized by both: 1. Eating in a discrete period of time (e.g., within any 2-hour period) an

amount of food that is definitely larger than most people would eat in a similar period of time, and:

2. A sense of lack of control over eating during the episodes (e.g., a feeling that one cannot stop eating or control what or how much one is eating).

B. During most binge episodes at least three of the following behavioral indicators of loss of control are present:

228 AGRAS ET AL.

1. Eating much more rapidly than usual 2. Eating until uncomfortably full 3. Eating large amounts of food when not feeling physically hungry 4. Eating large amounts of food throughout the day with no

planned mealtimes 5. Eating alone because of being embarrassed by how much one is

eating 6. Feeling disgusted with oneself, depressed, or feeling very guilty

after overeating C. The binge eating occurs, on average, at least twice a week for a 6-month

period. D. The binge eating causes marked distress. E. The binge eating does not occur exclusively during the course of Bulimia

Nervosa and the individual does not abuse medication (e.g., diet pills) in an attempt to avoid weight gain.

Potential subjects were also excluded if they were currently involved in a weight loss program, were taking antidepressant medication or any medication that might influence weight, if they exhibited sufficient suicidality to make outpa- tient treatment with desipramine dangerous, if they abused drugs or alcohol, if there was a history of purging within the prior 12 months, or if their BMI was below 27. The latter criterion excluded individuals who did not meet criterion for the treatment of overweight.

Over 500 women who responded to advertisements were screened in a tele- phone interview aimed at minimizing exclusions at the next level of assessment. Exclusions at this point included the use of antidepressant medication, individuals who did not binge eat (e.g., those not reporting eating large amounts of food in their binges), individuals who were currently purging, or those who did not meet the binge frequency criterion for BED. From the group initially responding to the advertisement, 210 women were invited to participate in the study. Of these, 161 individuals followed through with a clinical interview conducted by a Ph.D. psychologist. At the beginning of this interview, the project was described in detail to the potential participant in order to facilitate in- formed consent. Of these potential participants, 18 did not meet criteria for binge eating disorder or had current bulimia nervosa. One individual met criteria for alcohol abuse and another was actively suicidal. The remaining women could not meet the time commitment for the study, leaving 108 women who were entered into the study. Unfortunately, no reliability of diagnosis, (e.g., interview by a second clinician) was carried out. However, 20070 of the interview protocols were examined by an observer uninformed as to the diagnosis, and a 100070 agreement was found for the diagnosis (or not) of BED.

The participants' ages ranged from 22 to 65 years (M = 45.0, SD = 10), and subjects reported an onset of binge eating at a mean of 19 years (SD = 10.7) and an onset of overweight at 15.5 years (SD = 10.2). Participants' pretreatment weight averaged 104.9 kg (SD = 18.5) and they reported binge eating 4.5 times per week (SD = 1.4). The average size of the largest binge (in a 2-day period) for a subset of these subjects whose pretreatment self- monitoring records were analyzed (N = 40) was 1326 kcal. BMI averaged 38.6 (SD = 6.6). Fifty-five percent of the participants had a college degree (34°70

TREATMENT OF BINGE EATING DISORDER 229

had attended graduate school), 38~70 had attended college but had not ob- tained a degree, and the remainder had either graduated from high school or had attended high school.

Experimental Conditions and Design Following the screening interview, subjects were weighed, their height was

measured, and they were asked to monitor their eating behavior for 2 weeks. They then attended a further session to complete the baseline assessments. Subjects were then allocated by means of a predetermined randomization schedule to one of the three experimental groups. Thirty-seven participants were allocated to weight loss therapy (WL), 36 to cognitive-behavioral therapy followed by weight loss therapy (CBT/WL), and 36 to cognitive-behavioral therapy followed by weight loss therapy and desipramine (CBT/WL-D). Six Ph.D. therapists, all of whom were skilled in CBT and WL therapies, were balanced across conditions.

Weight loss therapy. Participants allocated to this condition attended 30 group sessions, weekly for the first 24 weeks and then biweekly. Each session lasted 90 minutes. Therapy was based on the LEARN Program for Weight Control (Brownell, 1985), which was modified for use with this particular population and extended to a 30-week program. Material specifically dealing with methods to overcome binge eating (or loss of control over eating) was removed from the manual to minimize overlap with cognitive-behavioral therapy. How- ever, the consumption of three meals each day and eating heart-healthy food, elements overlapping with cognitive-behavioral therapy, were considered in- tegral to the weight loss program. Manuals given to each participant contained the information covered in each of the sessions, as well as specific assignments for the coming week. The focus of therapy was on making gradual lifestyle changes in diet, exercise, and eating habits. A diet aiming at a weight loss of about one pound per week was suggested, and participants were encouraged to experiment in order to find the level of caloric intake that allowed them to meet this goal. The importance of reducing fat intake and increasing the intake of complex carbohydrates was stressed. Relapse prevention techniques were introduced toward the end of the program. Participants self-monitored different aspects of their behavior over the 30-session program, including food intake, exercise, and thoughts concerning food. At each session, the self- monitoring of participants was reviewed, problems were aired, and the group was challenged to find solutions to particular problems. In addition, the new material for the week was reviewed together with the assignment for the coming week. Therapy did not focus on the problem of binge eating, rather the focus was on weight loss, and weight was monitored at each session throughout treatment.

Cognitive-behavioral therapy. This treatment was based on the manual used by Telch et al. (1990) in their controlled study of the treatment of BED. Par- ticipants assigned to this condition attended 12 weekly sessions, followed by 18 sessions of the weight loss therapy described above. Group leaders explained to participants that the first 12 weeks of treatment would focus on their binge eating problem, following which they would engage in treatment for weight loss. The rationale given to participants was that binge eating develops as a

230 AGRAS ET AL.

response to dieting, which leaves individuals feeling deprived and hungry, hence promoting further binge eating. Following a binge, individuals with this disorder resolve to diet again, setting themselves up for a vicious circle of dieting and binge eating. Hence, it was explained to participants that it is necessary to overcome binge eating before beginning a gradual weight loss regimen. Par- ticipants were taught to monitor their food intake, binge eating episodes, and thoughts and moods before and after binge eating. These records formed the focus of treatment, which aimed to gradually change the restricted and chaotic eating patterns so that participants established a regular pattern that included eating at least three well-balanced meals each day. Monitoring of binge eating and the following procedures were specific to CBT. Participants were taught to reduce the avoidance of "forbidden foods" in order to enhance self-control and minimize feelings of deprivation. Precipitants to episodes of binge eating were examined in detail and more adequate coping behavior devised for han- dling such antecedents (e.g., negative mood). Distorted thinking concerning forbidden foods, dieting, and shape and weight were also addressed. Finally, relapse prevention procedures specific to binge eating were introduced during the last few sessions. Participants were not weighed during this treatment phase.

Desipramine treatment. Following the completion of cognitive-behavioral therapy, participants assigned to receive desipramine in addition to weight loss therapy were seen in small groups either immediately before, or immediately following, the weight loss groups. These groups met weekly for the first 4 weeks, biweekly for 4 weeks, and then at 4-week intervals. The group sessions were conducted by a psychiatrist who explained the rationale for the use of the medication, i.e., that a previous controlled study had demonstrated effectiveness of this medication in reducing binge eating and that although the mecha- nism of action was not certain, it appeared that hunger and emotional lability may be reduced by the medication. Potential side effects were explained to the participants, as well as methods to counteract these problems. Participants were started on 25 mg of desipramine and this dose was increased depending on side effects as well as therapeutic effects to a maximum dose of 300 mg, usually given as a single dose at night. The brief group sessions addressed the progress of the participants in terms of binge eating and weight loss, medication side effects and how to deal with them, and adherence to the medication regimen. Desipramine was discontinued over a 2-week period following the posttreatment assessment. The mean dose of desipramine was 285 mg with a mean blood level of 212 ng/mL. Twenty-four percent of participants in this group discontinued desipramine before the posttreatment assessment because of side effects.

Assessments

Each participant attended five assessments: at baseline, at 12 weeks (on completion of CBT or 12 weeks of WL treatment), at 24 weeks, and at 36 weeks (posttreatment assessment). A follow-up assessment was held 3-months posttreatment. The primary outcome measures in this study were frequency of binge eating and percentage change in weight.

Primary measures. The two primary measures were of binge eating and


weight. The assessment of binge eating is fraught with methodologic problems, because such assessments, whether collected by interview of self- monitoring, rely upon self-report that is sensitive to the demand characteristics of a treatment outcome study. Assessment of the frequency of binge eating at all time periods, including baseline, was based on a 1-week period of self- monitoring during which caloric intake and each binge episode were recorded by the participant, and by recall collected by an assessor uninformed as to the subject's condition for a second consecutive week. We chose to use the number of days in which the participant reported one or more binges, rather than the actual number of binges, since the division into binge episodes is arbitrary for many individuals (e.g., for those who "graze" during a whole day). Binges were defined for the participants as "episodes of eating during which you ate more than most people would eat in that situation and/or felt out of control, e.g., you could not stop eating." Hence, days characterized by either or both "objective," i.e., large binges and feeling out of control, and "subjective," i.e., smaller binges characterized by loss of self-control, were counted (Cooper & Fairburn, 1987). This would appear to be the most con- servative method of assessing binge eating because even if participants changed their binges from large to small over the course of the study, as seems likely from our experience to date, the day would still count as a binge day. For example, Smith et al. (1992) reported that objective binges were entirely eliminated by CBT, while subjective binges were reduced but not eliminated, sug- gesting that the experience of out of control eating takes longer to change than eating large amounts of food in a binge. For a subset of 19 subjects who self-monitored for a week pretreatment and at 24 and 36 weeks and were con- tinuing to binge eat, the average size of binges, including both objective and subjective binges, was 731 kcal, 601 kcal, and 590 kcal, respectively, indicating continued consumption of large quantities of food, albeit with some improve- ment over time as might be expected.

Weight was assessed on a balance beam scale with the participant wearing indoor clothing without shoes.

Secondary measures. The secondary measures in this study were administered at each assessment and included the Beck Depression Inventory (BDI) (Beck, Ward, Mendelson, Mock, & Erbaugh, 1961), a measure of depressed mood, and the Three Factor Eating Questionnaire (Stunkard & Messick, 1985), which measures cognitive restraint, tendency toward disinhibition of eating, and per- ceived hunger.

Statistical Analysis A repeated measures ANOVA was performed for each primary and sec-

ondary outcome variable to determine group x time significance. For this comparison only subjects with data at each time point were used (WL: N = 27; CBT/WL: N = 30; CBT/WL-D: N = 27). When a significant difference was found, an ANCOVA, controlling for the baseline value of the variable under consideration, was performed at each individual time point (12, 24, and 36 weeks) to determine where the differences occurred (for percentage change in weight an ANOVA was used because the baseline value for each subject

232 AGS.AS Er hr.

was set at 0). The difference between the groups at a particular time point was then determined by pairwise comparisons. All tests were two-tailed. It should be noted that, at 12 weeks, the groups receiving CBT were combined and compared with the group receiving weight loss therapy.

Results Pretreatment

There were no significant pretreatment differences between groups for the two primary outcome measures, days binged, and weight. A significant difference between groups was found for disinhibition (p < 0.03) and for restraint (p < 0.01), see Table 1 for the group means and standard deviations.

Dropouts Ten subjects (27%) allocated to WL dropped out of the study during the

36-week treatment period, compared with 6 subjects (17%) allocated to CBT/WL, and 8 subjects (23°70) allocated to CBT/WL-D. These proportions were not significantly different from one another.

Primary Outcome Measures There was a significant interaction between group and time, F(6, 243) =

2.38, p < .03, for the number of days binged. A post-hoc ANCOVA revealed that the groups differed at 12 weeks with CBT (67% reduction in binge eating) superior to WL (44% reduction in binge eating), F(I, 81) = 7.05, p < .01. There was also a significant interaction between group and time for percent weight change, F(4,166) = 6.4, p < .001. A post-hoc ANOVA revealed that the group differed at 12 weeks, F(1,84) = 10.7, p, < .002, with WL (loss of 2.0 kg) superior to CBT (gain of 0.7 kg).

At 36 weeks, 41% of participants in the CBT/WL-D group, 37% of those in the CBT/WL group, and 19% in the WL group, were no longer binge eating; these percentages were not significantly different. Weight losses for the three groups were 6.0 kg (CBT/WL-D), 1.6 kg (CBT/WL), and 3.7 kg (WL), respectively, a non-significant difference between groups.

Secondary Outcome Measures No significant differences were found between the groups for either depres-

sion, as measured by the BDI, or for dietary restraint. There was a significant interaction between group and time for disinhibition, F(6,222) = 2.36, p < .04, with an ANCOVA showing a difference between groups at 24 weeks, F(2, 73) = 4.4, p < .02. The group receiving desipramine was superior (i.e., less disinhibited) to WL treatment, F(1,45) = 7.7, p < .008. In addition, there was a significant interaction between group and time for hunger, F(6,222) = 2.18, p < .05, and an ANCOVA found a significant difference between groups at 24 weeks, F(2,73) = 5.7, p < .005. Both the group receiving desipramine, F(1,45) = 90, p < .004, and the group receiving CBT/WL F(1,49) = 5.4, p < .03) were significantly superior to WL, with both groups reporting lower hunger levels than WL.

TREATMENT OF BINGE EATING DISORDER

TABLE 1 MEANS AND STANDARD DEVIATIONS FOR THE T m ~ GRouPs AT PKETREATMENT,

12, 24, AND 36 WI~EKS

233

Pretreatment 12 weeks 24 weeks 36 weeks

Weight (kg) WL 102.9 + 15.8 a 100.9 + 16.8a 100.4 + 17.3a 99.2 + 16.9a CBT/WL 102.1 + 15.7a 102.7 + 16.5b 100.7 + 16.7 a 100.5 + 17.6a CBT/WL-D 111.9 ± 17.4 a 112.7 + 18.5 b 107.0 + 20.1 a 105.9 + 20.5a

Binges/wk WL 4.5 + 1.6a 2.5 + 1.9a 1.2 ± 1.2a 1.5 + .2a CBT/WL 4.4 + 1.4a 1.5 ± l a b 1.1 ± 1.1a 1.2 ± 1.3a CBT/WL-D 5.1 + 1.4a 1.8 ± 1.3b 1.6 ± 1.8a 0.9 ± 0.9a

BDI WL 12.9 + 6.5a 11.6 ± 8.0a 11.2 + 8.5a 11.3 + 10.3a CBT/WL 13.5 + 7.8a 12.7 + 9.2a 8.5 + 6.5a 8.9 + 7.6a CBT/WL-D 13.7 + 8.1a 10.8 + 8.9a 8.6 + 8.2a 7.8 + 7.8a

Disinhibition WL 13.7 + 1.8a 12.7 + 2.6a 11.7 + 3.0a 11.6 + 2.6a CBT/WL 14.0 + l.lab 12.7 + 1.8 a 10.8 + 2.7ab 10.8 + 3.1 a CBT/WL-D 14.6 ± 1.2 b 12.2 + 2.3 a 9.7 ± 3.5b 10.2 ± 4.2a

Hunger WL 10.3 ± 2.9a 9.4 ± 3.2 a 8.5 + 3.2 a 8.4 + 3.2 a CBT/WL 9.1 ± 2.9a 7.8 + 3.1 a 6.2 ± 2.9b 6.4 + 3.2 a CBT/WL-D 10.6 + 2.6a 8.3 ± 2.4 a 5.8 + 3.1b 7.2 + 2.8a

Restraint WL 8.7 ± 4.5a 11.2 + 5.1 a 12.5 + 5.1 a 12.0 + 5.1a CBT/WL 6.6 ± 2.8b 8.5 ± 3.5a 10.8 ± .4 a 10.9 + 4.5a CBT/WL-D 8.2 ± 3.6a 10.4 ± .5a 14.6 ± 3.3a 13.4 ± 3.4 a

a,b For each variable, groups within time period with different subscripts differ significantly (p

< .05). WL (Weight loss treatment), CBT/WL (cognitive-behavioral therapy followed by weight loss treatment), CBT/WL-D (cognitive-behavioral therapy followed by weight loss treatment and desipramine). For the 12-week analysis the CBT groups were combined.

Effect of Abstinence on Weight Change In a post-hoe analysis, participants were separated into those who were ab-

stinent for binge episodes or not at 12 weeks independent of treatment assignment, and the effect of abstinence on weight change was examined for that and subsequent assessments. Those who were abstinent at 12 weeks had lost significantly more weight than those who were not abstinent, both at 12 weeks (loss of 3.3 kg versus gain of 2.0 kg, p < .006) and at 24 weeks (loss of 6.2 kg versus loss of 2.0 kg, p < .03), but not at 36 weeks (losses of 6.2 kg and 3.1 kg, respectively).

234 AGKAS ET AL.

Follow-up At the 3-month posttreatment follow-up (1 year after beginning treatment),

a further six subjects in the WL group, five subjects in the CBT/WL group, and three subjects in the CBT/WL-D group, were unavailable for assessment. The WL group had lost 4.15 kg from baseline, the CBT/WL group had no change in weight from baseline, while the CBT/WL-D group had lost 4.8 kg. These changes were not significantly different from each other. When the two groups receiving CBT were compared, a significant interaction of group by time was found, F(3,41) = 3.76, p < .02. The group receiving CBT/WL-D lost significantly more weight than the CBT/WL group (p < .05). All groups demonstrated a significant relapse in the frequency of binge eating from the 36-week to the 52-week assessment period, WL (2.0 binge days/week, 1407o abstinent), CBT/WL (1.7 binge days/week, 2807o abstinent), and CBT/WL-D (1.5 binge days/week, 3207o abstinent).

Discussion The aim of this study was to explore methods to reduce binge eating and

enhance weight loss in patients with binge eating disorder. Two hypotheses were explored. The first was that the use of CBT prior to WL treatment would facilitate abstinence from binge eating, which in turn would facilitate weight loss in this difficult patient population. The second was that antidepressant medication would add to the effectiveness of WL therapy by enhancing restraint and helping to maintain abstinence from binge eating. Unfortunately, the weight losses achieved by the groups in this study were not impressive. In a 1-year weight loss program, Perri et al. (1988) reported weight losses of 12.45 kg, approximately double that of our most successful group. Nonethe- less, during the first 12 weeks of therapy, the only point of direct comparison between CBT and WL therapies, CBT was significantly superior to weight loss treatment in reducing binge eating. This advantage was not found at later time points in this study. In addition, weight loss treatment was significantly superior to cognitive-behavioral therapy in inducing weight loss during the first 12 weeks of treatment, but once again this advantage was lost at subsequent assessments. Adding desipramine to CBT/WL resulted in a statistically significant larger weight loss at follow-up. In addition, desipramine reduced disinhibition more effectively than did weight loss therapy alone. This suggests that the emotional regulation offered by desipramine may be useful in weight regulation (change in disinhibition was positively correlated with weight loss at 36 weeks r = 0.21, p < .05).

The dropout rates experienced in this study appear similar to those reported in comparable studies. The 36-week dropout rate for CBT/WL in this study was 17070, compared with 17070 in the Telch et al. (1990) study, and 11070 in the Smith et al. (1992) study, the latter studies being of 12 and 16 weeks dura- tion respectively. The dropout rate at 12 weeks for CBT in our study was 6070, lower than that for the comparable studies. The dropout rate for the WL condition at 27070 is comparable to the 23070 reported by Perri et al. (1988) in their 1-year long weight loss study. At 12 weeks the dropout rate for the WL group


was 13%. The only comparable study reporting dropout rates for desipramine was that of McCann et al. (1990), with a dropout rate of 33% in a 12-week study, compared to 23% in the present study. Nonetheless, such dropouts may affect the statistical interpretation of the data presented in this paper.

For patients becoming abstinent from binge eating early in treatment, weight losses were significantly greater than for those who did not achieve abstinence. In fact the latter patients increased their weight during the first 12 weeks of treatment. Hence, there was a relationship between abstinence and weight loss as hypothesized, with early abstinence appearing to facilitate weight loss, as described by Smith et al. (1992). Abstinence was associated with a 92070 probability of weight loss: any other level of reduction in binge eating was associated with less than a 60070 probability of weight loss. Yet, despite this, the treatments did not differ in outcome at 36 weeks. The latter finding may be due to two factors. First, some individuals became abstinent from binge eating in the weight loss group, reducing the difference between groups in this re- spect, and second, the abstinence rates for CBT were lower than expected.

There are several possible reasons why the abstinence rates in this study were lower than in previous studies. First, as pointed out by Smith et al. (1992), the Telch et al. (1990) study which found abstinence rates of nearly 80070 used only a 1-week reporting period for binge eating, compared to 2 weeks in the current study and 4 weeks in the Smith et al. (1992) study. The abstinence rate in the latter study was 50070, larger than that following 12 weeks of CBT in the present study i.e., 20070, but not as different from the abstinence rate at 36 weeks in the present study, viz., 37 070. Hence, assessment differences may partially account for the lower abstinence rates observed in the present study. In addition, differences in recruitment methods and study aims may have resulted in a somewhat different patient population to those entered into previous studies. This study addressed both binge eating and weight loss: previous studies have focused exclusively on binge eating. The average pretreatment weight of our participants was 225.9 lb compared with 191.2 lb in the Smith et al. (1992) study, 191 lb in the Telch et al. (1990) study, and 198.8 lb in the McCann et al. (1990) study. Hence, the selection of a population specifically interested in reducing both binge eating and weight may have resulted in the recruitment of a heavier sample of women, perhaps more difficult to treat than a somewhat less obese sample. The participants in this study were also slightly older, at 45 years, than those in other treatment studies: 41.9 years (Smith et al. 1992), 42.6 years (Telch et al., 1990). The average frequency of 4.1 binge days per week at baseline was similar to those reported in other studies: 3.2 (McCann et al., 1990), 3.4 (Smith et al., 1992), 4.2 (Telch et al., 1990).

The fact that weight loss therapy led to a decrease in binge eating equivalent to that of cognitive-behavioral therapy at all points following the 12-week assessment is of interest. The dietary instructions that are part of weight loss treatment overlap to some extent with the behavior change procedures used in cognitive-behavioral therapy. These shared elements may account for the similarity in results, although it should be noted that at 12 weeks, when weight loss therapy was directly compared with cognitive-behavioral therapy, that CBT was superior to WL in reducing binge eating. A recent study of the effects

236 AGRAS ET AL.

of a Very-Low-Calorie-Diet (VLCD) on binge eating revealed that binge eating was markedly reduced during the dietary phase of treatment, followed by a gradual relapse as food was reintroduced over the next few months (Telch & Agras, 1993). This may suggest that the critical element afforded by the weight loss therapy regimen in reducing binge eating is in the narrowing of the range food cues consequent upon following a diet. Such narrowing is most marked when patients are consuming only a VLCD.

It is important to consider what guidance the results of this study offer for future investigations of the overweight patient with BED. First, because abstinence from binge eating may be related to more successful weight loss, it seems important to enhance abstinence rates in future studies. One method of at- taining this goal would be to treat participants who fail to become abstinent following cognitive-behavioral therapy with a second treatment. Because interpersonal therapy has been demonstrated to be useful in this group of patients (Wilfley et al., 1993), this approach to treatment, quite different from cognitive-behavioral therapy, might be used in an attempt to improve abstinence rates. Second, many participants gained weight during the initial cognitive-behavioral therapy and then had to lose that extra weight before reducing their weight below baseline levels. It therefore seems appropriate to provide the expectation that weight should remain stable during cognitive- behavioral therapy, and to add weekly weighings, an exercise module, and edu- cation concerning fat intake, to the cognitive-behavioral therapy module. Third, as discussed earlier, other medications might be investigated, either as first line treatments, or for those who do not respond to initial treatment with either medication or psychosocial therapy. Finally, we need to consider the pos- sibility that a more appropriate goal for this population is to stem future weight increases. Here a waiting-list control condition would be useful to assess the rate of weight gain in untreated individuals with BED. Although halting weight gain may prove disappointing to the majority of our participants, it may be more realistic and may also be more successful than a weight loss approach, because when weight loss results in relapse many individuals report that they continue to gain weight inexorably.

In conclusion, this study demonstrates that we have much to learn concerning the joint goals of reducing binge eating and weight in patients with binge eating disorder. Furthermore, this study provides no evidence that either cognitive- behavioral therapy or desipramine add to the effectiveness of weight loss therapy.

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RECEIVED: June 10, 1993 ACCEPTED: November 1, 1993

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Weight loss, cognitive-behavioral, and desipramine treatments in binge eating disorder. An additive design