Development and Testing of Measures to Assess Weight-Related Motivations for Dieting in Eating Disordered Individuals. A Thesis

Transcription

1 Development and Testing of Measures to Assess Weight-Related Motivations for Dieting in Eating Disordered Individuals A Thesis Submitted to the Faculty of Drexel University by Yelena Chernyak M.S. in partial fulfillment of the requirements for the degree Doctor of Philosophy May 2010

2 ii Dedications I thank my parents Gregory and Maria Chernyak for their encouragement of my professional pursuit in the field of psychology, despite my breaking the mold. Conor Larkin has grown alongside me throughout graduate school and provided daily support and motivation. Moreover, I dedicate this thesis to Lev Burdin, a grandfather who first instilled a love for learning and was always one of the best examples of perseverance out there.

3 iii Acknowledgements I would like to thank my mentor, Michael R. Lowe Ph.D., for his continued support and mentorship over the last 5 years. He has shared his unsurpassed expertise and passion in the development of this project. I would also like to thank the committee reviewing this thesis for their valuable feedback Dr. Evan Forman, Dr. Jacqueline Kloss, Dr. Doug Bunnell, and Dr. Katherine Presnell. The Renfrew Center in Philadelphia, PA provided the opportunity to study a clinical sample of high relevance for this project. Antonia O Planick contributed greatly to the implementation of this project within the Renfrew Center. Her dedication to high quality data was essential. I thank all of the members of the Lowe Lab for their guidance, support, and collaboration over the years in this project and many others!

4 iv Table of Contents LIST OF TABLES..viii ABSTRACT... ix 1: INTRODUCTION State of Current Research Prevalence of Eating Disorders Treatment Bulimia Nervosa Background and Previous Study Re-evaluating Motivation to Diet in Bulimia Nervosa Importance of Drive for Objective Thinness in Bulimia Nervosa Utility of the DFOT Study Objectives Testing the Reliability and Validity of DFOT Hypotheses Anorexia Nervosa Historical Relevance Dieting Motivation in Anorexia Nervosa Limitations to the Construct of Fear of Fatness Development of a Novel Measure 24 Fear of Treatment Goal Weight Determining treatment goal weight.26 Advantages to assessing FTGW Study Objectives Testing the Reliability and Validity of FTGW Exploratory Hypotheses : METHOD Participants..38

5 v Inclusion Criteria Procedure Measures GFFS EDI-II DFOT FTGW EDE-Q BDI Weight Status Weight History Treatment Completion : STATISTICAL ANALYSIS Bulimic Group DFOT Cross-Sectional Prospective Analyses Anorexic Group FTGW Cross-Sectional Prospective Analyses Test Re-test Reliability Treatment Completion Controlling for Type-I Error Statistical Assumptions Power Analysis : RESULTS Descriptive Statistics BNS Group Cross-Sectional Analyses Predictive Analyses..69

6 vi Exploratory Analyses 71 Predictive ability of existing measures..71 Predictive ability of DFOT independent of existing measures..71 GFFS..72 DFT ANS Group Cross-Sectional Analyses Predictive Analyses Exploratory Analyses 77 Predictive ability of existing measures..77 Predictive ability of FTGW independent of existing measures 77 GFFS..78 DFT 78 5: DISCUSSION Overview of Results Sample Selection DFOT in Bulimia Nervosa Spectrum Individuals Psychometric Properties of DFOT Relationships of Existing Measures of Motivation for Dieting with DFOT Relationship of Motivations for Dieting with Weight Status Relationship of DFOT with Measures of Psychopathology Course of DFOT throughout Treatment The DFOT does not Predict Weight Status The DFOT Identifies Individuals who Stay in Treatment DFOT Predicts Level of Eating Disordered Psychopathology Predictive Abilities of Existing Measures of Motivation for Dieting Utility of DFOT Beyond Existing Measures of Motivations of Dieting 97 Prediction independent of GFFS Prediction independent of DFT..98 Combined variance of existing measures and DFOT 99

7 vii Implications FTGW in Anorexia Nervosa Spectrum Individuals Psychometric Properties of DFOT Relationships of Existing Measures of Motivation for Dieting with FTGW Relationship of Motivations for Dieting with Weight Status Relationship of FTGW with Measures of Psychopathology Course of FTGW throughout Treatment The FTGW does not Predict Weight Status The FTGW Does not Identify Individuals who Stay in Treatment FTGW Predicts Level of Eating Disordered Psychopathology Predictive Abilities of Existing Measures of Motivation for Dieting Utility of FTGW Beyond Existing Measures of Motivations of Dieting.112 Prediction independent of GFFS..113 Prediction independent of DFT 113 Combined variance of existing measures and FTGW Implications Limitations Future Directions : LIST OF REFERENCES.121 APPENDIX A: Goldfarb Fear of Fatness Scale APPENDIX B: EDI-II Drive for Thinness and Body Dissatisfaction Subscale 132 APPENDIX C: Drive for Objective Thinness Scale.134 APPENDIX D: Fear of Treatment Goal Weight Scale..136 APPENDIX E: Eating Disorders Examination Questionnaire.138 APPENDIX F: Beck Depression Inventory APPENDIX G: Weight History Questionnaire.144 Vita. 146

8 viii List of Tables 1. Table 1: Inclusion Criteria for Restricted Samples Based on Diagnosis Table 2: Sample Characteristic Means and Standard Deviations Table 3: Correlations between Measures of Motivations for Dieting and Psychopathology at Admission to Treatment Table 4: Prediction of Treatment Outcome by Measures of Motivation for Dieting Table 5: Prediction of Treatment Outcome by Existing Measures of Eating Disordered Psychopathology Table 6: Prediction of Treatment Outcome by Motivations for Dieting Beyond Level of Existing Measure Table 7: Listing and Comparison of Significance Levels Between Full and Restricted Samples....84

9 ix ABSTRACT Development and Testing of Measures to Assess Weight-Related Motivations for Dieting in Eating Disordered Individuals Yelena Chernyak M.S. Michael R. Lowe Ph.D. Motivations for dieting are an important dimension to evaluate in the development and maintenance of eating disorders such as Anorexia Nervosa (AN) and Bulimia Nervosa (BN). Existing measures for these disorders have a number of limitations. Drive for thinness has been implicated as an important factor in BN. However, measures of this construct, such as the Drive for Thinness scale (DFT), appear to measure a desire to be thinner, but not the radical dieting mentality thought to contribute to the development of disordered eating. The Drive for Objective Thinness (DFOT) scale was developed by the author to assess desire to be objectively thin. The DFOT was previously found to be uniquely endorsed by a clinical population of individuals with BN compared to other motivations for dieting and helped to differentiate pathological from non-pathological dieting. In the current study, the DFOT displayed sufficient internal consistency and validity in a clinical population and was similarly related to associated forms eating disordered psychopathology compared to established measures such as the GFFS, EDE, and EDI. The DFOT significantly predicted treatment outcomes in BN spectrum individuals including various forms of psychopathology and length of stay.

10 x A secondary goal of this study was to develop a measure which assesses how motivated AN individuals are to avoid treatment goal weight, defined as 90% of ideal body weight. The Fear of Treatment Goal Weight Scale (FTGW) removed the subjectivity that terms such as fatness possess by providing an objective body weight and had greater variability than fear of fatness among ANs. An initial use of the FTGW established sufficient internal consistency and validity in a clinical population. These novel measures were similarly related to associated forms eating and mood disordered psychopathology compared to established measures. Over the course of treatment, FTGW increased in AN individuals and significantly predicted treatment outcomes in this population. Both the DFOT and FTGW appeared to have incremental validity in predicting multiple outcomes above established measures of motivations for dieting. Utilization of these novel measures may be important in combination with existing measures of psychopathology for identifying individuals who are most appropriate for treatment. Moreover, the high endorsement of these measures in eating disordered psychopathology highlights the need for treatment approaches to address these treatment resistant constructs.

11 Prevalence of Eating Disorders 1: INTRODUCTION 1.1 State of Current Research Bulimia Nervosa (BN) is a serious psychiatric problem, with increasing prevalence in recent years (APA, 2000). Lifetime prevalence rates for this disorder range from 1-3%. This disorder is characterized by out of control eating and use of compensatory mechanisms to affect body weight or shape (APA, 2000). Medical complications resulting from BN include fluid electrolyte imbalances, cardiac and skeletal myopathies, menstrual irregularity, and dental damage (Milosevic, 1997). These can be especially severe for those bulimic individuals who engage in vomiting, diuretic, or laxative misuse. BN is also associated with a number of psychiatric problems, including depression, anxiety, social withdrawal, and interpersonal difficulties (Bulik, 2002; Herzog, Nussbaum, & Marmor, 1996; Wonderlich & Mitchell, 1997). Lifetime prevalence for anorexia nervosa (AN) in females is.5% (APA, 2000). The mortality rate for anorexia nervosa is the highest of any psychiatric disorder, at 7% for 10-year follow-up and 15-20% for 20-year follow-up (Crisp, 1997; Halmi, 1998). Medical complications are often life threatening in AN and include dehydration, endocrine abnormalities, low blood pressure, cardiac and skeletal abnormalities, and anhedonia (Treasure & Szmukler, 1995). Similar to BN, AN is associated with numerous other psychological disorders (APA, 1993) Treatment The current gold standard treatments of choice for eating disorders produce remission in only half of afflicted patients. For BN, Cognitive-Behavioral Therapy (CBT) produces abstinence from binge eating and purging in approximately 40-50% of

12 2 treatment completers (Keel, Mitchell, Miller, Davis, & Crow, 1999; Mitchell, Halmi, Wilson, Agras, & Crow, 2002). While this treatment has impressive empirical support for its efficacy, it fails for over half of those completing treatment. CBT has been shown to be superior to a variety of other treatment approaches, including Behavior Therapy (Fairburn, Jones, & Peveler, 1991), self-monitoring (Agras, Schneider, Arnow, Reaburn, & Telch, 1989), nutritional counseling (Wilson & Fairburn, 20002), anti-depressant medications (Wilson & Fairburn, 2002), stress management (Wilson & Fairburn, 2002), and exposure with response prevention (Cooper & Steere, 1995). Interpersonal psychotherapy (IPT) for BN also received promising empirical support compared to CBT (Fairburn, Jones, Peveler, Hope, & O Connor, 1993). However, CBT produced better results at the cessation of treatment compared to IPT (Agras, Walsh, Fairburn, Wilson, & Kraemer, 2000). The two treatments appear to be effective for the same group of individuals with BN, remaining ineffective for approximately half of those who initiate treatment (Agras, Walsh, Fairburn, Wilson, & Kraemer, 2000; Fairburn, Marcus, & Wilson, 1993). Experts in the field, including Fairburn, Shafran, and Cooper (1999), note that existing treatment options for BN are not effective enough (p.514). Anorexia nervosa requires some of the most lengthy and expensive mental health treatment (Streigel-Moore, Petrill, Garvin, & Rosenheck, 2000). Inpatient hospitalization, lengthy treatment stays, and repeat admission characterize the typical course of AN treatment. Recovery rates for this disorder are low, where only a minority of patients establish a secure recovery (Kordy et al., 2002). Literature on the effectiveness of psychological treatments for AN is limited (Bulik, Berkman, Brownley, Sedway, & Lohr, 2007). Few controlled studies of psychological treatments for AN have

13 3 been conducted. From the available studies, CBT for AN has been shown to have treatment completion rates ranging from 46-73% (Halmi et al., 2005) and remission rates of 15-70% after treatment (Pike, 1998). When CBT for AN was compared to other psychological treatments for AN, no significant differences were found (Vitousek, 2002). Existing treatments appear to be ineffective for the majority of patients with AN and little is known about effective psychological treatment for AN. Given the current prognostic outlook, it is vital to investigate further what may contribute to treatment resistance in both BN and AN. In addition, given the amount of resources expended on treatments with unfavorable outcomes, it is necessary to find a meaningful way to identify those individuals who would be most likely to benefit from existing treatments. A review of the literature, study objectives, and hypotheses will be presented separately for BN and AN in this document. This allows for a comprehensive explanation of the development, maintenance, and treatment that is unique to each eating disorder. Additionally, differences in assessment exist between BN and AN and will be highlighted separately.

14 4 1.2 Bulimia Nervosa Background & Previous Study Dieting, particularly among normal weight women, has been a controversial topic in recent years (Brownell & Rodin, 1994; Polivy & Herman, 1987; Wooley & Garner, 1994). Drive for thinness, in particular, has been implicated as an etiological factor for the development of dieting and, ultimately, disordered eating. The restraint model of Herman and Polivy has long argued that societal norms favoring extreme thinness are largely to blame for dieting in non-obese women (Herman & Polivy, 1987). They suggested that the current societal preference for a thin physique has spawned a corresponding societal preoccupation with dieting (p. 635, Herman & Polivy). Moreover, the restraint literature suggests that this societal preference for thinness is translated into a personal drive to become thin in restrained eaters. Herman and Polivy suggest that because of weight concerns, women are induced to strive toward a condition of ruddy cheeked emaciation (p. 635). The cognitive-behavioral model of bulimia (Fairburn, Marcus, & Wilson, 1993) also identifies concepts such as drive for thinness (Tasca, Illing, Lybanon-Daigle, Bissada & Balfour, 2003) and internalization of the thin ideal (Thompson & Stice, 2001) as key dimensions that are widely viewed as contributing to the cause and maintenance of BN. Several different measures have been developed to assess drive for thinness and related constructs. What the literature often refers to as drive for thinness or internalization of the thin ideal has been measured with instruments that do not appear to measure motivation to be abnormally thin. For example, the most widely used measure of drive for thinness is the EDI-II s Drive for Thinness Subscale (DFT). However, this

15 5 Drive for Thinness subscale includes questions which target avoidance of weight-gain, instead of a drive to become objectively thin (e.g. I am terrified of gaining weight or I feel extremely guilty after overeating ) (Tasca, et al. 2003). The DFT appears to measure a desire to be thinner, but not the desire to reach an emaciated weight thought to contribute to the development of disordered eating. Similarly, Stice s Thin-Ideal Internalization Scale (Stice & Thompson, 2001) also does not mention an unhealthy level of thinness (e.g. I would like my body to look like the women that appear in TV shows and movies, Slender women are more attractive ). The lack of an appropriate measure to assess a drive to become abnormally thin means that a dimension that appears to be central to the development or maintenance of bulimia nervosa (BN) has not been sufficiently researched. Although most bulimic individuals are in the normal weight range when they present for treatment, many individuals with BN reach very low weights in the process of developing their disorder (Butryn, Lowe, Safer, & Agras 2006; Garner and Fairburn, 1988). BN usually begins with a period of radical dieting and significant weight loss that often results in reaching an objectively thin body weight (Fairburn & Cooper, 1984). In fact, one third of bulimic patients have a history of AN (Butryn et al.; Garner & Fairburn, 1988; Russell, 1979). Given that a substantial portion of individuals with BN were motivated to achieve an objectively thin body weight during the development of their disorder, it is a problem that existing measures of drive for thinness have not been truly measuring a drive to be skinny. Approximately two-thirds of American women who are overweight or obese (Flegal, Carroll, Ogden, & Johnson, 2002; Hedley, Ogden, Johnson, Carroll, Curtin, & Flegal, 2004) and many of those still in the normal weight range are understandably

16 6 concerned about being or becoming overweight. Because of the rise in the prevalence of overweight and obesity in the last 30 years, it is not surprising or necessarily pathological that most women would like to be thinner and in better shape than they are. This suggests that a measure assessing motivation to reach an objectively thin body weight would be useful in differentiating dieting motivations that may reflect an eating disordered mentality from those that do not Re-evaluating Motivation to Diet in Bulimia Nervosa The weight histories of bulimic individuals are consistent with the notion that dieting and eating disordered behavior may be motivated by both a desire to be thin and a fear of weight gain. Evidence indicates that many bulimic individuals have both a history of overweight (Fairburn, Welch, Doll, Davis, & O Connor, 1997) and lose substantial weight in the process of developing their disorder (Butryn, et al. 2006; Garner & Fairburn, 1988). The following section summarizes the weight-loss and weight-gain pattern many bulimic individuals undergo. Prior to the onset of the disorder, individuals with BN have been shown to have a greater history of personal and familial overweight than their non-bulimic counterparts (Fairburn et al., 1997; Garner & Fairburn, 1988). As discussed above, most bulimic individuals experience a dramatic diet-induced weight loss before developing binge eating and purging (Fairburn & Cooper, 1984). Approximately one-third of bulimic patients have a personal history of AN as a result of the significant weight loss at the initiation of their disorder (Butryn et al., 2006). Most bulimic individuals are unable to maintain the level of dietary restriction necessary to stay at their new and significantly lower weight and a pattern of bingeing and purging often develops at this point (Fairburn,

17 7 & Cooper, 1984; Fairburn, Cooper, Doll, Norma, & O Connor, 2000). This pattern is responsible for an upward weight trajectory where BN individuals usually regain some, but not all, of the weight they lost during the development of their disorder (Garner & Fairburn, 1988). By the time most BN individuals present for treatment, they are primarily in the normal weight range (Garner & Fairburn, 1988; Russell, 1979). However, they are also weight suppressed that is they weigh significantly less than their highest weight ever. Weight suppression produces a more efficient metabolic rate and makes this group more susceptible to weight gain (Leibel, Rosenbaum, & Hirsch, 1995). In fact, weight suppression prospectively predicts weight gain during inpatient treatment and poorer treatment outcome (Butryn et al., 2006). Thus, fears of weight gain may be grounded in reality for many bulimic patients, both because of their pre-morbid tendency toward overweight and because their current weight suppressed state may make them susceptible to weight gain. The fact that most bulimic patients were sufficiently motivated to diet and lose a substantial amount of weight in the past suggests that they may still be motivated to return to a sub-normal body weight. As a result, many bulimic individuals may endorse a pathological desire to be at an extremely thin weight for their height. Thus, many bulimic individuals may experience both a heightened fear of fatness and a strong drive for objective thinness because they have actually experienced both the dreaded state of higher adiposity and the idealized state of extreme thinness.

18 Importance of Drive for Objective Thinness in Bulimia Nervosa Questions have been raised in past literature regarding what motivates bulimic individuals to undertake a radical weight loss diet (Polivy & Herman, 1985, Polivy & Herman, 1987). Given that traditional measures of dieting motivation such as the Drive for Thinness (DFT) subscale do not actually appear to measure a drive to become thin, but a drive for thinness, scores of past studies that have measured drive for thinness and related constructs may not be able to tell us much about the role of a need to become thin. Instead, these studies describe only the role of wanting to be thinner or avoiding obesity (neither of which are necessarily pathological goals). Endorsement of an objectively thin body weight by BN individuals may reflect what is thought to be one of the most pathological dieting motivations in this disorder (Keys, Brozek, Henschel, Mickelson, & Taylor, 1950; Russell, 1979). However, prevailing theoretical and treatment models do not account for the drive for objective thinness or the significant weight loss that occurs in the etiology of BN. Moreover, those models that include the concept of drive for thinness are mistaking a drive for thinness (which is usually not pathological) with a drive for objective thinness (which is often pathological). Because of a lack of existing measures in the field and a need to identify the construct that may underlie radical dieting practices in BN, Chernyak and Lowe (2010) developed the Drive for objective thinness (DFOT) scale. The DFOT is designed to assess respondents motivation to achieve an objectively thin body weight, defined as being 15% below the medically ideal body weight for a respondent s height. The DFOT excludes items regarding fear of fatness or avoidance of weight gain.

19 9 Chernyak and Lowe (2010) compared the newly developed DFOT measure and two more traditional measures of weight-related motivations. The EDI-II Drive for Thinness sub-scale (DFT), Goldfarb s Fear of Fatness scale (GFFS; Goldfarb, Dykens, & Gerrard, 1985), and the DFOT were compared among nonclinical unrestrained eaters (UREs) and restrained eaters (REs), and a clinical group of individuals with BN spectrum eating disorders. REs can be identified by the Herman & Polivy Restraint scale (1985). Unrestrained eaters served as controls. The clinical group was composed of women in an intensive treatment program with a diagnosis of BN or EDNOS-bulimic spectrum. Herman and Polivy have suggested that those with the greatest history of dietary restraint may eventually become eating disordered (Polivy & Herman, 1985). Restrained eaters were studied as an analogue of the process that presumably contributes to the development of BN (Polivy & Herman, 1985). Drive for Thinness (DFT) and Fear of Fatness (GFFS) were found to be highly and significantly correlated (r=.871; p <.001) amongst all participants. This strong relationship between DFT and GFFS was much greater than the relationship of DFOT with DFT or GFFS. DFT appeared to actually be measuring a construct that is more similar to fear of fatness or avoidance of weight gain than to a desire to be objectively thin. This is noteworthy because many researchers have assumed that drive for thinness also represents a drive to become objectively thin, and our results indicate that this is not a valid assumption. This conclusion is based both on the very high correlation between DFT and GFFS and the nature of many of the DFT items (discussed above). To the extent that DFT does reflect a desire to be thinner (not thin ), it appears that what most normal weight nonclinical respondents mean by thinner is to lose a small

20 10 amount of weight, not to lose enough weight to become skinny or objectively thin (defined as 15% below the medically appropriate weight for their height). The foregoing arguments suggest that the very high correlation between DFT and GFFS is a reflection of DFT measuring a construct that is best characterized as avoidance of weight gain or, at most, a desire to be somewhat thinner. An alternative conclusion is that the correlation between DFT and GFFS is due to the measurement of a true drive for thinness by GFFS. However, face validity of GFFS shows that all items explicitly refer to weight gain or its consequences. Chernyak and Lowe (2010) found a significant interaction between weight-related motivation (i.e. DFOT, DFT, & GFFS) and eating disordered group, composed of nonclinical unrestrained and restrained eaters and individuals with bulimic spectrum eating disorders. While DFT and GFFS were elevated in restrained eaters (REs), DFOT was not any higher in this group than in unrestrained eaters (UREs). The traditional assumption that normal weight REs drive for thinness reflects an unhealthy need to be skinny appears to be incorrect. Instead, they appear to be motivated to diet mostly by a fear of fatness. The clinical group of BN women scored significantly higher than their nonclinical counterparts (UREs and REs) on all three measures of dieting motivation (GFFS, DFT, & DFOT). This suggests that bulimic individuals may be highly motivated in their dieting behavior by both a fear of weight gain and a drive for objective thinness, unlike REs who are primarily motivated by a fear of weight gain. For bulimic women, GFFS and DFOT may both motivate extreme dieting practices which in turn could fuel binge eating and purging. Because past weight loss appears to play a major role in the development of

21 11 binge eating (Fairburn & Cooper, 1984), those bulimic patients scoring highest on DFOT may be caught in a double bind - they want to lose weight to attain a thin body but losing weight may increase their binge eating and therefore their susceptibility to weight gain. Discussed below are some further steps to investigate the role of DFOT in women diagnosed with BN Utility of the DFOT The newly developed DFOT scale may be useful in the assessment and treatment of bulimic patients. For assessment purposes, DFOT was found to differentiate clinical and nonclinical groups better than existing measures that assess fear of fatness and avoidance of weight gain (GFFS & DFT; Chernyak & Lowe, 2010). Additionally, relinquishing radical dieting is key to making progress with Cognitive Behavioral Therapy (CBT) for BN, which is the currently the gold standard treatment of choice for this disorder (Fairburn et al., 1991). If a patient remains strongly motivated to be objectively thin, they may be reluctant to relinquish the type of radical dieting which CBT requires. Therefore, DFOT might be useful in identifying bulimic individuals most appropriate for CBT. DFOT is not correlated with an individual s current weight, lowest- weight-ever (LWE), or level of weight suppression (WS). These are all elements of personal weight history that can affect the psychopathology of an eating disordered individual. However, there was no relationship between DFOT and either dimension. Therefore, DFOT captures a psychological variable that is not related to personal weight history. Psychological variables which are not rooted in personal weight history may be more amenable to treatment in bulimic patients (Butryn et al., 2006). As a result, DFOT might be well suited for clinical interventions.

22 12 Chernyak and Lowe (2010) also showed a high level of variability on DFOT scores, as evidenced by a high standard deviation (relative to the mean) among bulimic individuals (M=50.0, SD=12.3). Scores on the GFFS showed less variability among the sample (M=33.2, SD=4.2). The data suggest that there is a greater level of variability on DFOT compared to GFFS. This is consistent with the argument that fear of fatness will be uniformly elevated in individuals with BN because it is a criterion for BN. Although this supports the idea that fear of fatness is a salient and highly endorsed psychological motivation for BN, it does not allow for GFFS to meaningfully differentiate the individuals who endorse it. The newly developed DFOT has a much higher level of variability, which suggests it may be more useful for differentiating individuals level of unhealthy dieting motivation Study Objectives The main purpose of this project was as a validity test of the newly developed Drive for Objective Thinness scale. The DFOT was also used to predict prognosis of treatment in individuals with BN. It is important to note that the DFOT was not being evaluated for mediation. Therefore, this project is not proposing that DFOT accounts for the relation between eating disorder diagnosis and treatment outcome or explains why a particular treatment outcome was achieved. The combination of vulnerability to weight gain and continued efforts at weight-loss may perpetuate the symptoms of many bulimic individuals. To the extent that BN individuals have a motive for extreme thinness (DFOT), they may also be unwilling to relinquish dietary restraint and compensatory mechanisms because they believe that doing so could undermine weight loss or produce weight gain. For a portion of bulimic

23 13 individuals who have a susceptibility to weight gain, relinquishing eating disordered behaviors may result in weight gain and weight gain is typically abhorrent to bulimic individuals. This may become an impediment to successful treatment particularly in those individuals who are most motivated to achieve, maintain, or return to an objectively thin body weight. Testing the Reliability and Validity of the DFOT The first portion of the current study evaluated data both at admission and over the course of inpatient treatment in a sample of women diagnosed with Bulimia Nervosa or EDNOS-BN. DFOT was compared to EDE-Q subscale scores, EDI-II subscales scores, percent of ideal body weight, GFFS, and BDI. Based on past data on the DFOT, an overall positive relationship between the DFOT and eating disordered psychopathology at admission was predicted. Holding percent of ideal body weight constant (IBW), those scoring highest on the DFOT should be the most concerned about achieving an abnormally thin body weight and potentially the most dissatisfied with their current body weight. As a result, this group may be the most motivated to engage in dietary restriction and compensatory mechanisms in order to achieve the objectively thin goal weight. The EDE-Q and EDI-II subscales assess this type of eating disordered pathology and are predicted to correlate positively with the DFOT. The Weight Concerns, Eating Concerns, and Restraint subscales of the EDE-Q and Bulimia subscale of the EDI-II would reflect high levels of bulimic psychopathology which might be consistent with an elevated DFOT. The EDI-II Body Dissatisfaction subscale may also be elevated in those individuals who endorse DFOT. Presumably, the

24 14 more driven a BN individual is to achieve a body size that is objectively thin, the more dissatisfied they would be with their current body size. Individuals who remain strongly motivated to achieve an objectively thin weight, assessed by the DFOT, may be the least willing to engage in treatment at the Renfrew Center. This group may be most resistant to normalizing their eating patterns, letting go of dietary restraint, and abstaining from bingeing, purging, and other compensatory mechanisms because these are the pathways they believe will bring them closer to an objectively thin weight. However, these individuals are in a controlled eating environment with limited control over their food intake. Additionally, compensatory mechanisms such as binge eating, purging, or dietary restriction are not allowed during treatment. Because the DFOT may represent one of the most pathological drives for continued eating disordered psychopathology in BN, this measure was expected to predict changes in symptom improvement over the course of treatment. A higher DFOT at admission was expected to predict less improvement on the EDE-Q and EDI-II subscales at treatment completion. For example, scores on the Weight-Concerns subscale of the EDE-Q and Body Dissatisfaction subscale of the EDI-II may be greater in those individuals who endorse an objectively thin body weight because they are no longer allowed to engage in severe dietary restriction or compensatory mechanisms in order to achieve this ideal while in treatment. It was important to control for weight change in this analysis, as some individuals experience weight [re-]gain as part of treatment due to a normalization of their eating patterns. Those individuals who are engaging in treatment the most by adhering to their

25 15 meal plan may experience weight gain and a resurgence of a drive for objective thinness, as treatment moves them farther away from their desired weight goals. Therefore, analyses were conducted with and without controlling for weight change from admission to discharge. DFOT was expected to predict weight change over the course of treatment. There is reason to believe that those individuals who are the most committed to an objectively thin weight may be the least likely to adhere with components of treatment that require weight gain. This group may be strongly motivated to secretly compensate for caloric intake or manipulate eating requirements. Those individuals who strongly endorse the DFOT may resist the weight gain which occurs in a portion of bulimic individuals during treatment (Butryn et al., 2006). Therefore, those scoring highest on the DFOT were predicted to have the least increase in weight between admission and treatment completion. Moreover, individuals who endorse DFOT the most may be the least likely to tolerate the nature of treatment for BN, which requires normalization of eating and the potential for weight gain. As a result, high DFOT was predicted to have a higher frequency of AMA (against medical advice) premature treatment drop-out. Lastly, it is possible that the DFOT may be predictive of increased eating disordered psychopathology and symptoms, rather than improvement, post discharge. Because residential treatment represents an artificial and controlled environment, bulimic individuals are restricted in their use of eating disordered behaviors. Meanwhile, their body dissatisfaction may be increasing due their inability to pursue their weight loss goals or even because of weight gain during treatment. As a result, discharge from residential treatment may present an opportunity for those highest on drive for objective

26 16 thinness to begin restricting their intake again, resulting in an increase in binge eating and purging. Renfrew is able to collect 1-month follow-up data on about 60% of those who complete the discharge measures. These data may be explored in a secondary analysis to test for the predictive ability of DFOT post treatment Hypotheses 1. A positive relationship between DFOT and eating disordered psychopathology measured by the EDE-Q Weight Concerns, Eating Concerns, and Restraint Subscales in bulimic individuals at admission to treatment was predicted. 2. A positive relationship between DFOT and eating disordered psychopathology measured by the EDI-II Body Dissatisfaction and Bulimia subscales in bulimic individuals at admission to treatment was predicted. 3. A positive relationship between DFOT, GFFS, and DFT in bulimic individuals at admission to treatment was predicted. 4. Higher levels of endorsement of DFOT was expected to predict poorer treatment outcome in bulimic individuals, including less improvement on the EDE-Q Weight Concerns, Eating Concerns, and Restraint subscale scores and EDI-II Body Dissatisfaction subscale scores, controlling for percent of ideal body weight and length of stay in treatment. 5. Higher levels of endorsement of DFOT was expected to predict less weight gain during treatment, controlling for length of stay.

27 Historical Relevance 1.3 Anorexia Nervosa The phenomenon of anorexia nervosa-like symptoms has been documented for centuries. Symptoms of emaciation and refusal to eat have been described since the 1200 s across many cultures (Keel & Klump, 2003). In early medieval times, women with these symptoms were often viewed as saints who suffered from holy anorexia, motivated by the belief that the ability to go without food reflected divine intervention. Historical cases of so-called fasting girls were observed throughout the 19 th century, primarily identified by a refusal to eat, emaciation, and, in some cases, death. Similar to earlier cases of refusal to eat in European medieval saints, the fasting girls served as an example of religious inspiration. In both instances, documented cases show that an inability to eat may have been part of the pathology. In the case of fasting girls, documented accounts show that some of these girls were highly resistant to refeeding, even under medical advice, and may have endorsed a weight phobia (Keel & Klump). The understanding of anorexia nervosa (AN) by investigators of the disorder and the experience of AN by the patients themselves has, presumably, changed over time. While AN has always been characterized primarily by a very low body weight in the absence of medical illness, the focus on body size and fatness has been relatively new. Keel and Klump observe that Although there is universal agreement that AN represents a disorder marked by starvation, some have argued that weight phobia represents an aspect of a culturally bound illness that is not necessarily related to the disease that underlies AN (2003, p,749; Banks, 1992, 1997; Katzman & Lee, 1997; Lee, 1995; Palmer, 1993).

28 18 In the last century, the incidence of AN has increased in Westernized countries such as the United States and Great Britain (Garner, Garfinkel, Schwartz, & Thompson, 1980; Wiseman, Gray, Mosimann, & Ahrens, 1992). The disproportionate increase of anorexia in these countries has led to the notion that AN is a culture-bound syndrome, particularly linked to the idealization of thinness which accompanies Westernization. However, AN exists in non-western cultures where over-evaluation of body size or idealization of thinness are not cultural norms. It does not appear to be the case that AN is a culture-bound syndrome (Keel & Klump, 2003). Although the modern conceptualization of AN centers on body dissatisfaction and fear of fatness, there is tremendous variation in the psychopathology of the AN individual. The presence of weight concern as a motivating factor was not found to be universal in an investigation by Keel and Klump (2003). Lee and colleagues (1993) found that in non-western cultures such as Hong Kong, the majority of AN cases (59%) did not report weight concerns. In such instances, gastric discomfort or illness were cited as the reason for food refusal and subsequent self-starvation. It is important to note that AN individuals may provide alternate explanations for their food refusal other than an underlying motivations for weight loss (Lee, Lee, Ngai, Lee, & Wing, 2001). However, the authors make the claim that this portion of participants truly did not exhibit weight concerns. Lee, Ho, and Hsu (1993) and Lee (2000) support this argument by showing that with increased Western influence in China, and, presumably, an introduction to Western ideals of thinness, presentation of weight phobia in AN increased. Based on these data, an atypical but relevant minority of cases do not exhibit and may never develop an obsession about body size which is thought to be a hallmark of this disorder.

29 19 The two pieces of evidence above suggest that the rapid weight loss defining AN seems to be fairly stable across times and cultures, but the psychopathology of AN focusing on fatness seems to be specific to time and place. In a review on the historical origins of AN, Keel and Klump concluded that weight concerns [in AN] may be a culturally bound phenomenon restricted to the sociohistorical context that idealize thinness and denigrate fatness. ( 2003, p.755) While common to the presentation of AN, fear of fatness may not be the most unique or pathological element for anorexia nervosa. It is possible that fear of fatness is not the primary factor driving anorexia, but a post hoc explanation based on prevailing sociocultural norms for a puzzling disease brought on by other, yet unknown, factors. Perhaps those with AN would not fear weight gain to the extent that they do if they could be assured that it is possible to gain weight only to a level that will restore their physical health (e.g. treatment goal weight and not above). It becomes important to evaluate the utility of fear of fatness among other measures of anorexic psychopathology in the assessment and treatment of this disorder Dieting Motivation in Anorexia Nervosa Anorexia Nervosa (AN) is a severe psychiatric disorder characterized by a refusal to maintain body weight at a medically appropriate level (APA, 2000). The American Psychiatric Association and Cognitive-Behavioral theory place body image disturbances and weight concerns at the center of this disorder (APA, 2000; Fairburn, Cooper, & Shafran, 2002). A hallmark feature of AN is a distortion in the way that the body weight or shape is experienced. While most individuals with AN can accurately report their low

30 20 body weight, they often describe themselves as fat or obese despite their emaciation (Fairburn & Brownell, 2002). Williamson, Cubic, and Gleaves (1993) define body dissatisfaction as the discrepancy between current and ideal body size. Studies using silhouettes to depict body size have found that AN women judge their current body size to be larger than it really is while endorsing an exceedingly thin ideal, which results in a high level of body dissatisfaction (Williamson et al., 1993). Consistent which these results are studies which show many AN individuals may mislabel their emaciated state as normal or overweight or deny the seriousness of their currently low body weight (Steinglass, Eisen, Attia, Mayer, & Walsh, 2007). It is possible that although many AN individuals know that they are objectively thin, they do not perceive themselves as such. Instead, many AN individuals are thought to perceive themselves as fat, and have a morbid fear of fatness (Rushford, 2006). Steinglass et al. (2007) report that at least two-thirds of individuals with AN report a dominant belief that any normal eating behaviors would result in immediate fatness or weight gain. Even when emaciated individuals do not report fear of weight gain, a minor increase in weight may trigger an intense fear of becoming fat and stall further therapeutic gains (Rushford, 2006). In summary, most individuals with AN would acknowledge their low weight, but judge themselves to be fat and morbidly fear any weight gain Limitations of the Fear of Fatness Construct Irrational beliefs about shape and weight, including a morbid fear of fatness are a central diagnostic criterion for AN (APA,2000). Past literature has assumed that one of the most pathological drives sustaining AN symptoms is a morbid fear of fatness

31 21 (Garfinkel & Garner 1982; Goldfarb et al., 1985; Morgan & Russell, 1975;Wilson, Hogan, & Mintz, 1985). However, most AN individuals have never experienced the dreaded state of fatness. AN individuals are typically low or average on body weight even prior to the onset of their disorder. A multisite study of AN treatment found that the average pre-morbid body mass index (BMI) was across five sites in samples of adolescent females (Steinhausen, Grigoroiu-Serbanescu, Boyadjieva, Neumarket, & Metzke, 2008). These BMIs are comparable to the 50 th percentile for females at this age (Kuczmarski et al., 2000). Steinhausen and colleagues (2008) also found the same low BMI before and long after this group of AN individuals developed their disorder, which suggests that upon recovery AN individuals are not at risk for overweight or obesity. Evaluating family history of individuals with AN also does not reveal parental overweight or increased vulnerability to weight gain (Halmi, Struss, & Goldberg, 1978). Halmi et al. (1978) compared control families to the families of AN individuals on height and weight, while controlling for age and socio-economic status. No significant relationship was found between the weight of the patients and controls parents in this study, suggesting that the parents of AN individuals do not have an increased predisposition to weight gain compared to controls. There is no evidence that those with AN have a heightened risk for overweight. On the contrary, both the average pre-morbid and long-term follow-up weights after recovery suggest that AN individuals are constitutionally thin. Moreover, focusing on fear of fatness as the primary psychopathology of AN has a number of limitations. Goldfarb s Fear of Fatness Subscale (GFFS) is a measure developed to assess this construct in individuals with bulimia and anorexia nervosa. The

32 22 GFFS was used to establish that women with AN were more fearful of becoming fat than control female college students (Goldfarb et al., 1985). A limitation of the GFFS is that it fails to provide an objective definition of fatness. Without an objective weight anchor, the concept of fatness becomes inherently subjective. Because AN individuals view any weight gain as making them fat, there is an inability to differentiate between distinct degrees of weight gain (since all weight gain equates to fatness ). For example, among anorexic individuals, the GFFS may be unable to distinguish between a fear of fatness where fatness is interpreted as an obese weight of 200 pounds, a normal weight of 130 pounds, or a still-emaciated weight of 86 pounds for an individual with AN who currently weights 85 pounds. Another measure developed to asses fear of fatness and complement the GFFS is the Fear of Gaining Weight (FGW) scale (Rushfod, 2006). This FGW is a self-report visual analogue scale which invites the participant to indicate how afraid of gaining weight they are by intersecting a horizontal line between Not at all to Completely. The FSW was found to be a valid measure of fear of weight gain and was strongly related to the GFFS (Garner, 1991; Gleaves, Williamson, Eberenz, & Barker, 1995) and the EDI- II Drive for Thinness subscale, the latter of which was shown to be composed of items that appear to measure fear of fatness (Chernyak & Lowe, 2010). However, the FTGW also fails to provide objective standard for weight gain. Thus, the FSW is subject to the same problem as the GFFS. It is unable to distinguish between a fear of gaining 5 pounds, 15 pounds, or 50 pounds. A subsequent problem shared by GFFS and FSW is that is that fear of fatness (or weight gain ) is a criterion for AN. It is universal by definition (APA, 2000) and

33 23 endorsed by the vast majority of individuals with this disorder. Because fear of fatness is a criterion for the diagnosis of AN, it is impossible to measure variation in this construct among those with AN. It is possible that while all individuals with AN fear weight gain to a level of objective fatness, which is rational, it is more likely that a target in the normal weight range might be associated with more individual differences among AN individuals than simply fear of fat. This might be especially true if an AN patient were to believe that they could remain at a normal weight for the rest of their lives, thereby removing the possibility that they would ever become objectively overweight or obese. While most professionals in the field would agree that fear of fatness is an important dimension in the study of anorexia nervosa, it is possible that existing measures such as the GFFS and FSW may not be very informative due to the inherent subjectivity of their items and the uniformity in the construct they are trying to measure. It is critical to detect what does differentially motivate individuals with AN to engage in eating disordered behaviors and how this relates to treatment outcomes. Since individuals with AN may be largely incapable of differentiating between different amounts of weight gain (because any weight gain makes them feel fat or fatter), it might be valuable to make this differentiation for them. This differentiation would have the capacity to distinguish individuals who fear weight gain to a level of objective fatness, which, if accurate, could be rational, from those individuals who fear weight gain that results in a return to normal body weight. It is possible that in the same way that a drive for objective thinness targeted a previously unmeasured but relevant motivation for dieting in individuals with BN, a resistance to returning to the normal weight range may be a useful dimension in the study of what sustains AN. This type of resistance in AN individuals represents a novel