Maintenance Treatment for Anorexia Nervosa: A Comparison of Cognitive Behavior Therapy and Treatment as Usual

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1 REGULAR ARTICLE Maintenance Treatment for Anorexia Nervosa: A Comparison of Cognitive Behavior Therapy and Treatment as Usual Jacqueline C. Carter, PhD 1,2 * Traci L. McFarlane, PhD 1,2 Carmen Bewell, MA 1,3 Marion P. Olmsted, PhD 1,2 D. Blake Woodside, MD 1,2 Allan S. Kaplan, MD 1,2,4 Ross D. Crosby, PhD 5 ABSTRACT Objective: The aim of this study was to compare two maintenance treatment conditions for weight-restored anorexia nervosa (AN): individual cognitive behavior therapy (CBT) and maintenance treatment as usual (MTAU). Method: This study was a nonrandomized clinical trial. The participants were 88 patients with AN who had achieved a minimum body mass index (BMI) of 19.5 and control of binge eating and purging symptoms after completing a specialized hospital-based program. Forty-six patients received 1 year of manualized individual CBT and 42 were in an assessment-only control condition (i.e., MTAU) for 1 year. This condition was intended to mirror follow-up care as usual. Participants in both the conditions were assessed at 3-month intervals during the 1-year study. The main outcome variable was time to relapse. Results: When relapse was defined as a BMI 17.5 for 3 months or the resumption of regular binge eating and/or purging behavior for 3 months, time to relapse was significantly longer in the CBT condition when compared with MTAU. At 1 year, 65% of the CBT group and 34% of the MTAU group had not relapsed. Discussion: The current findings provide preliminary evidence that CBT may be helpful in improving outcome and preventing relapse in weight-restored AN. VC 2008 by Wiley Periodicals, Inc. Keywords: anorexia nervosa; cognitive behavior therapy; relapse prevention (Int J Eat Disord 2009; 42: ) Introduction Accepted 13 August 2008 Supported by MOP from The Canadian Institutes of Health Research and by MH from The National Institutes of Health and by The Ontario Mental Health Foundation. *Correspondence to: Jacqueline C. Carter, Toronto General Hospital, 200 Elizabeth Street EN8-241, Toronto, Ontario, M5G 2C4, Canada. jacqueline.carter@uhn.on.ca 1 Department of Psychiatry, Toronto General Hospital, University Health Network, Toronto, Canada 2 Department of Psychiatry, University of Toronto, Toronto, Canada 3 Department of Clinical Psychology, York University, Toronto, Canada 4 Center for Addiction and Mental Health, Toronto, Canada 5 Neuropsychiatric Research Institute, Fargo, North Dakota Published online 23 October 2008 in Wiley InterScience ( DOI: /eat VC 2008 Wiley Periodicals, Inc. Anorexia nervosa (AN) is a serious psychiatric disorder that is associated with significant psychiatric comorbidity, severe medical complications, and major impairments in psychosocial functioning. Relapse following successful initial treatment is a significant contributor to the generally poor prognosis of this illness. Nutritional rehabilitation and weight restoration, frequently involving a period of day hospital or inpatient treatment, often constitutes the first step in the recovery process. Rates of relapse ranging from 9 to 65% following weight restoration have been reported, depending upon the definitions of remission and relapse used. 1 5 Remarkably few randomized controlled treatment studies on AN have been conducted and maintenance treatments designed to prevent relapse following successful initial treatment of AN are just beginning to be studied. To our knowledge, only four published controlled studies have examined maintenance treatments for AN to date. 2 4,6 Two of the studies evaluated psychological treatments and the other two were medication trials. Eisler and colleagues 4 found no difference in the rates of relapse at 5-year follow-up among 21 patients who were randomly assigned to receive either family therapy or individual supportive therapy for 1 year following weight-restoration in a hospital-based program. 7 In a randomized trial of 33 patients, Pike and colleagues found preliminary evidence that individual cognitive behavior therapy (CBT) was superior to nutritional counseling in preventing relapse following inpatient weight restoration. 2 The results of the two medication studies were inconsistent. Kaye and colleagues reported 202 International Journal of Eating Disorders 42:

2 MAINTENANCE TREATMENT FOR ANOREXIA NERVOSA that the antidepressant medication fluoxetine was superior to placebo in preventing relapse in a randomized double-blind trial of 35 patients. 6 However, Walsh and colleagues did not find any benefit from fluoxetine in preventing relapse following weight restoration in a recent double-blind, placebo-controlled randomized trial of 93 AN patients who were also receiving individual CBT. 3 The current study was a secondary study linked to the Walsh trial 3 that was designed to gather preliminary data on the effectiveness of individual CBT for weight-restored AN. The aim of the present study was to compare the rate and timing of relapse in AN patients who received 1 year of manualized individual CBT versus patients who were in an assessment-only comparison condition (MTAU) for 1 year following initial weight restoration in a specialized hospitalbased treatment program. Method Design This study was a nonrandomized clinical trial. Two maintenance treatment conditions for AN following weight restoration were compared: individual CBT and maintenance treatment as usual (MTAU). The MTAU was an assessment-only naturalistic control condition. Both conditions lasted for 1 year. Assessments took place before and after the initial weight-restoration treatment as well as at 3-month intervals during the 1-year maintenance phase. The main outcome variable was time to relapse. Recruitment and Participants The participants were 88 consecutive female patients who met DSM-IV criteria for AN at the time of admission to the inpatient or day hospital program of the Toronto General Hospital Eating Disorders Program between August 2000 and July These programs have been described in detail elsewhere. 8,9 They are both intensive group therapy programs focused on nutritional rehabilitation through provision of supervised meals, weight restoration, interruption of binge eating and purging symptoms, and group psychotherapy. During the initial day hospital or inpatient treatment phase, all participants reached a body mass index (BMI) (kilograms/m 2 ) of at least 19.5 and maintained this weight for 2 3 weeks before participating in the current study. Informed consent was obtained at the end of the initial treatment phase. The study was approved by the Research Ethics Board of the Toronto General Hospital. Following completion of the initial day hospital or inpatient treatment phase, 46 of the 88 patients participated in a 1-year randomized controlled trial of fluoxetine to prevent relapse in AN a. The recently published results of this trial indicated that fluoxetine had no significant impact on the rate or timing of relapse. 3 In addition to fluoxetine or placebo, all of the patients in this trial simultaneously received manualized individual CBT. 2 The remaining 42 of the 88 patients were in an assessment-only comparison condition (MTAU). Of the 42 patients in MTAU, six (14.3%) did not meet the inclusion criteria for the fluoxetine/cbt trial, 18 (42.9%) were eligible but chose not to take part in the fluoxetine/cbt trial, and 18 (42.9%) presented for treatment just after the trial ended. Of the six patients who did not meet the inclusion criteria for the fluoxetine/cbt trial, 3 lived too far away, two exceeded the duration of illness criteria of 15 years (one had AN for 15.4 years and the other for 18.6 years), and one had a medical illness that prevented participation. Of those who were eligible but chose not to take part in the trial, the majority (77%) reported not wanting to take fluoxetine as their reason for declining to participate. Treatment Conditions Cognitive Behavior Therapy (CBT). Patients in this condition were eligible to receive 50 individual therapy sessions of 45 min duration with an experienced psychologist over a 1-year period. All the patients in the CBT condition concurrently received either fluoxetine or placebo. The average number of CBT sessions received by each participant during the trial was 38 sessions. The treatment was manual-based and involved three phases: (1) strategies to address behavioral dysfunction pertaining to eating and weight that increase the risk of relapse; (2) cognitive restructuring techniques pertaining to eating and weight; and (3) application of a schema-based approach to address a broad range of relevant issues that extend beyond eating and weight (e.g., interpersonal problems, developmental issues, self-esteem). 2 Patients could also have up to five supplemental sessions with family members or significant others. Therapists received detailed training and supervision by the first author of the treatment manual (Dr. Kathleen Pike) who had also conducted the previous CBT relapse prevention study. 2 Maintenance Treatment as Usual (MTAU). This was an assessment-only comparison condition. Patients in this condition were asked to seek follow-up care as usual. One option was to attend the aftercare program at our a Two of the original 48 patients in the previously published trial 3 were excluded from the current study because their BMI at admission to the day hospital phase was higher than 18. International Journal of Eating Disorders 42:

3 CARTER ET AL. TABLE 1. Follow-up treatment received by the MTAU group (n 5 35) a Type of Treatment Number % of Total Sample a Individual therapist Program aftercare group Physician Support group Dietician/nutritionist No treatment a Based on 35 participants (seven of the original 42 participants dropped out before any follow-up information was collected. They are not included in any further analyses). Some participants received more than one type of treatment. center. This consists of three 90-min group therapy sessions per week for up to 12 weeks. Patients who successfully complete this first phase may choose to attend a second phase consisting of one 90-min group therapy session per week for up to 6 months. Participants were not obligated to attend this option. Rather patients in the MTAU condition were free to obtain follow-up care in the community in a naturalistic fashion during the 1-year study; however, they could also choose not to seek any therapy if they so desired. All follow-up care received by patients in this condition was carefully assessed prospectively during the study and is summarized in Table 1. Assessment Protocol and Measures Patients were assessed at admission to the day hospital or inpatient program and again at discharge from the program. During the 1-year maintenance study, assessments took place at 3-month intervals. Each assessment lasted 60 min. Key Eating Disorder Features were assessed using the Eating Disorder Examination 10 and the eating disorder inventory (EDI). 11 In addition, weight and height were measured to calculate BMI. Other measures included the Beck Depression Inventory 12 and the Rosenberg Self-esteem Scale. 13 Definition of Relapse Two definitions of relapse based on the DSM-IV criteria were examined: (1) BMI less than or equal to 17.5 for three consecutive months and; (2) two or more episodes of binge eating and/or purging per week on average for 3 months. Statistical Analyses CBT and MTAU groups were compared at baseline on sociodemographic and eating-disordered characteristics using independent samples t-tests for continuous measures and chi-square for categorical measures. A Cox proportional hazards regression analysis 14 was used to compare CBT versus MTAU in terms of time to relapse for each of the relapse definitions above. Participants who dropped out before relapsing and those that completed the study without ever relapsing were treated as right-censored observations. Results Participant Characteristics The mean age of the 88 participants was 24.1 (SD 5 5.1) years. Thirty-seven (42%) of the 88 participants met criteria for the binge/purge subtype of AN, whereas the remaining 51 participants (58%) met criteria for the restricting subtype. The mean BMI at admission to the inpatient or day hospital program was 15.4 (SD 5 1.8) and at discharge it was 20.4 (SD 5 0.5). The average age at onset of AN was 18.5 (SD 5 4.2) and the average duration of illness was 5.6 years (SD 5 5.2). Eighty-four percent were single, 13% were married or cohabiting, 1% was divorced, and 2% did not provide their marital status. The ethnic distribution of the sample was 84% Caucasian, 3% Asian, 2% Afro-Caribbean 2% Hispanic, 1% West Indian, 1% Middle Eastern, and 6% of the sample did not identify their ethnicity. Baseline Differences At the time of discharge from the initial inpatient or day hospital treatment phase, patients in the CBT and MTAU conditions were quite similar (see Table 2). However, the CBT group had significantly higher EDI Drive for Thinness subscale scores (t (79) , p ). This variable was entered as a covariate in all subsequent analyses of differences between the two groups. Attrition Of the 46 participants in the CBT condition, eight were withdrawn from the study as treatment failures due to deteriorations in their clinical state, 10 dropped out of treatment prematurely before relapsing, and two were withdrawn for missing too many treatment sessions or not complying with the medication regime. Of the 12 participants who dropped out or were withdrawn before relapsing, outcome data was available for 92% of them because they agreed to continue with the follow-up assessment protocol. Twenty-six participants completed the entire 1-year CBT treatment protocol. Of the 42 participants in the MTAU condition, 12 dropped out of the study within the 12-month follow-up period in that they were unwilling to continue to participate in the assessments. No significant difference in drop-out rates was found between CBT and MTAU groups (B ; SE ; df 5 1; p ). 204 International Journal of Eating Disorders 42:

4 MAINTENANCE TREATMENT FOR ANOREXIA NERVOSA TABLE 2. Baseline descriptive information for CBT and MTAU a Variable Mean for CBT Group (SD) Mean for MTAU Group (SD) p-value BMI (preinitial treatment) (1.87) (1.65) 0.94 Baseline BMI (0.48) (0.54) 0.81 Age (4.45) (5.70) 0.67 Duration of illness (years) 5.05 (3.99) 6.08 (6.24) 0.37 Objective binge episodes/28 days b 1.38 ( 0.29 ( 0.28 Vomiting episodes/28 days b 3.05 ( 1.00 ( 0.34 Days of exercising/28 days 3.13 (5.65) 1.00 (3.73) 0.07 EDI drive for thinness (5.66) (6.10) 0.05 EDI bulimia 2.11 (4.23) 1.29 (1.90) 0.29 EDI body dissatisfaction (7.45) (7.76) 0.08 EDI ineffectiveness (7.75) (7.82) 0.72 EDI perfectionism 8.61 (4.73) 7.94 (4.15) 0.82 EDI interpersonal distrust 5.87 (4.81) 5.63 (4.37) 0.51 EDI interoceptive awareness 9.73 (5.32) 8.71 (6.46) 0.44 EDI maturity fear 5.39 (6.54) 4.03 (3.53) 0.27 EDE importance of shape 4.40 (1.78) 4.58 (1.63) 0.65 EDE importance of weight 3.75 (2.10) 3.74 (1.97) 0.99 RSES (6.51) (7.19) 0.84 BDI (11.35) (12.68) 0.58 Subtype AN-R 5 25, AN-BP 5 21 AN-R 5 26, AN-BP Ethnicity 0.38 Marital status 0.51 Employment status 0.45 a Differences assessed by t-test or Chi-square. b Analyses conducted only on participants with an initial diagnosis of AN-BP. FIGURE 1. Relapse survival functions: BMI 17.5 for 3 months (Drive for Thinness included as a covariate). [Color figure can be viewed in the online issue, which is available at FIGURE 2. Relapse survival functions: BMI 17.5 for 3 months or bingeing/purging at least twice a week for 3 months (Drive for Thinness included as a covariate). [Color figure can be viewed in the online issue, which is available at Outcome When relapse was defined as a BMI 17.5 for 3 months, time to relapse was significantly longer in the CBT condition when compared with MTAU (B ; SE ; df 5 1; p ) (see Fig. 1). At 1 year, 24.4% of the CBT group and 50.0% of the MTAU had relapsed. EDI Drive for Thinness at baseline was not significantly associated with time to relapse in this analysis (B ; SE ; df 5 1; p ). Similarly, when relapse was defined as either a BMI 17.5 for 3 months or the resumption of regular binge eating and/or purging behavior for 3 months, time to relapse was significantly longer in the CBT group (B ; SE ; df 5 1; p ) (see Fig. 2). At 1 year, 32.5% of the CBT group and 65.6% of the MTAU group met criteria for relapse using this definition. In this analysis, EDI Drive for Thinness at baseline was significantly associated with time to relapse (B ; SE ; df 5 1; p ). In terms of remission rates, 65% of CBT and 34% of MTAU remained remitted at 1 year. International Journal of Eating Disorders 42:

5 CARTER ET AL. Because the MTAU group included two participants who did not meet the duration of illness criteria for the CBT study, the previous analyses were repeated with duration of illness included as a covariate along with EDI Drive for Thinness subscale scores. Similar results were found when relapse was defined as either a BMI 17.5 for 3 months or the resumption of regular binge eating and/or purging behavior for 3 months, as time to relapse was found to be significantly longer in the CBT group than the MTAU group (B ; SE ; df 5 1; p ). Neither EDI Drive for Thinness scores nor duration of illness were significantly associated with time to relapse. Discussion Relapse following successful initial weight restoration treatment is a common clinical problem in the treatment of AN. The aim of this study was to compare a manualized form of individual CBT and maintenance treatment as usual (MTAU) in the relapse prevention treatment of AN using a quasiexperimental design. Eighty-eight patients with AN received either CBT or MTAU for 1 year after successfully completing day hospital or inpatient treatment. The MTAU condition was an assessmentonly comparison condition in which participants were able to seek available follow-up care in a naturalistic fashion. The results of this study provide preliminary evidence that CBT may be helpful in improving outcome and preventing relapse in AN in comparison with treatment as usual. The present findings are consistent with the results of a previous study that provided preliminary evidence of the effectiveness of CBT in the posthospitalization treatment of AN and used the same CBT treatment manual. 2 Together with Pike s results, the present data provide an important foothold for launching a larger randomized controlled trial of CBT for AN. An important limitation of the current study is that the participants were not randomly assigned to treatment conditions. The findings should therefore be interpreted cautiously and viewed as preliminary. Relapse was defined in terms of both weight loss to a BMI of 17.5 or less and resumption of regular binge eating or purging behavior. In both the cases, time to relapse was significantly longer in the CBT condition and the rate of relapse was approximately twice as high in the MTAU condition. A detailed comparison of the two groups indicated only one significant difference: the CBT group reported significantly higher baseline scores on the EDI Drive for Thinness subscale. This difference was statistically controlled in all analyses of group differences. However, because participants were not randomized to the study conditions, we cannot rule out the possibility that selection bias influenced the results. It is possible that the two groups were different on some other variable that was correlated with outcome but was not assessed. For example, a sizable percentage of participants in the MTAU group (42%) were eligible to take part in the CBT condition but chose not to do so. In the majority of cases (77%), this was related to a refusal to take the study medication. A similarly low rate of acceptance of medication treatment in AN has been found in previous treatment studies. 6,15 It is possible that there are differences between the participants who were unwilling to take fluoxetine and those who were willing to accept medication that may make them more responsive to psychotherapy. For example, it may be that the latter group was more motivated to change than the former. However, it is also possible that those who chose not to take medication were more motivated because they did not feel they needed medication to maintain their gains. Of note, the results of the medication study indicated that fluoxetine had no impact on the risk of relapse. 3 Another limitation of the current study is that the treatment received by participants in the MTAU condition was not controlled. Because this assessment-only comparison condition was intended to reflect follow-up care as usual in the community, MTAU participants were able to seek out follow-up care in a naturalistic fashion. Our results showed that participants in MTAU had a considerable amount of contact with health care practitioners in the community including therapists and physicians. This was an unexpected and somewhat surprising finding that points to the heavy burden of care associated with the illness, even among individuals who successfully complete specialized intensive treatment programs for AN. The majority of these individuals seek out multiple, costly forms of further treatment. However, these treatments did not seem to be effective, as 66% in the MTAU condition ended up relapsing (either in terms of weight or bingeing/purging behavior or both). Relatively high rates of attrition pose a serious problem for research on the treatment of AN, lowering sample sizes, and reducing statistical power. 15 In this study, those who dropped out of the CBT condition were dropping out of treatment whereas those who dropped out of the MTAU condition were essentially refusing to comply with the assessment protocol. A strength of the current study is 206 International Journal of Eating Disorders 42:

6 MAINTENANCE TREATMENT FOR ANOREXIA NERVOSA that outcome data were available for the majority of individuals who dropped out of CBT because most of them agreed to comply with the follow-up assessment protocol after dropping out of treatment. Thus, we were able to minimize missing data thereby increasing the reliability and generalizability of the findings. The results of this study have both clinical and research implications. First, the findings offer further preliminary support for the use of CBT in the relapse prevention treatment of AN. Establishing effective maintenance treatments for AN is crucial to preventing relapse and future hospital admissions. A next important step is to conduct a largescale randomized controlled study of CBT for AN in which CBT is compared to a psychotherapy control condition that controls for common factors but does not contain the specific therapeutic strategies of CBT. There is also a need to develop ways of disseminating evidence-based CBT to healthcare providers in the community on whom these patients rely heavily for help following intensive treatment. Finally, our findings suggest that although CBT in its current form is helpful for many patients, there is still considerable room for improvement. The authors thank Dr. B. Timothy Walsh and Dr. Kathleen M. Pike for their collaboration on this project. References 1. Carter JC, Blackmore E, Sutandar-Pinnock K, Woodside DB. Relapse in AN: A survival analysis. Psychol Med 2004;34: Pike KM, Walsh BT, Vitousek K, Wilson GT, Bauer J. Cognitive behavior therapy in the posthospitalization treatment of AN. Am J Psychiatry 2003;160: Walsh BT, Kaplan AS, Attia E, Olmsted M, Parides M, Carter JC, et al. Fluoxetine after weight restoration in AN: A randomized controlled trial. JAMA 2006;295: Eisler I, Dare C, Russell GF, Szmukler G, le Grange D, Dodge E. Family and individual therapy in AN. A 5-year follow-up. Arch Gen Psychiatry 1997;54: Keel PK, Dorer DJ, Franko DL, Jackson SC, Herzog DB. Postremission predictors of relapse in women with eating disorders. Am J Psychiatry 2005;162: Kaye WH, Nagata T, Weltzin TE, Hsu LK, Sokol MS, McConaha C, et al. Double-blind placebo-controlled administration of fluoxetine in restricting- and restricting-purging-type AN. Biol Psychiatry 2001;49: Russell GF, Szmukler GI, Dare C, Eisler I. An evaluation of family therapy in AN and bulimia nervosa. Arch Gen Psychiatry 1987; 44: Olmsted MP, Kaplan AS, Rockert W. Relative efficacy of a 4-day versus a 5-day day hospital program. Int J Eat Disord 2003;34: Woodside DB, Lackstrom JB, Shekter-Wolfson L. Marriage in eating disorders comparisons between patients and spouses and changes over the course of treatment. J Psychosom Res 2000; 49: Fairburn CG, Cooper Z. The Eating Disorder Examination, in Binge Eating: Nature, Assessment, and Treatment. Fairburn CG, Wilson GT, editors. New York: Guilford Press, 1993, pp Garner DM, Olmsted MP. Manual for Eating Disorder Inventory (EDI). Odessa, FL: Psychological Assessment Resources, Inc., Beck AT, Steer RA, Brown GK. BDI-II, Beck Depression Inventory: Manual. San Antonio, TX: Psychological Corp., Rosenberg M. Conceiving the Self. New York: Basic Books, Cox DR, Oakes D. Analysis of Survival Data. London, New York: Chapman and Hall, Halmi KA, Agras WS, Crow S, Mitchell J, Wilson GT, Bryson SW, et al. Predictors of treatment acceptance and completion in AN: Implications for future study designs. Arch Gen Psychiatry 2005;62: International Journal of Eating Disorders 42: