Section 2 Assessment and Practice Frameworks for Eating Disorders and Obesity

Assessment and Diagnosis of Eating Disorders

Kelly C. Berg and Carol B. Peterson

The assessment and diagnosis of eating disorders (EDs) are critical for identifying EDs and associated symptoms, formulating an accurate understanding of the client's disorder, and planning effective treatment. When conducted with skill and empathy, assessment procedures can also enhance the counseling relationship and deepen therapeutic engagement (Peterson, 2005). Several factors can complicate the accurate assessment and diagnosis of ED symptoms, including the client's unintentional or deliberate misreporting of information as a result of fear of forced treatment or secondary effects of malnourishment; the co-occurrence of overlapping psychopathological and medical complications, including depression; and the complexity of several of the ED diagnostic constructs, including binge eating and the overevaluation of shape and weight that can lead to confusion for both the client and the clinician. In this chapter, we inform the accurate assessment and diagnosis of EDs by discussing (a) the diagnostic criteria for EDs, (b) strategies for integrating ED assessment into a clinical interview, and (c) special considerations for the assessment and diagnosis of EDs. We conclude with a case example, summary of important points, and a list of additional resources.

Diagnostic Criteria for Eating Disorders

Two full-threshold EDs, anorexia nervosa (AN) and bulimia nervosa (BN), are formally identified in the Diagnostic and Statistical Manual of Mental Disorders (4th ed„ text rev.; DSM-IV-TR; American Psychiatric Association [APA], 2000). A third ED category, labeled eating disorder not otherwise specified (EDNOS), is also included in DSM-IV-TR to identify individuals with clinically significant ED symptoms who did not meet criteria for either AN or BN (APA, 2000). The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is set to be published in 2013 and will include several important changes to the diagnostic criteria for EDs. We describe the criteria sets for each DSM-IV-TR ED diagnosis next, along with details regarding how each criteria set will change in DSM-5.

For a diagnosis of AN, the DSM-IV-TR requires that the following four criteria be met: (A) minimal body weight for age, gender, and height; (B) fear of weight gain; (C) at least one symptom of cognitive dysfunction related to EDs (i.e., overevaluation of shape and weight, body image disturbance, or a denial of the seriousness of being at a low body weight); and (D) amenorrhea (i.e., missing three consecutive menstrual cycles; APA, 2000). Additionally, the DSM-IV-TR identifies two subtypes of AN. The restricting subtype is used to identify individuals who did not engage in regular binge eating or purging (i.e., self-induced vomiting, laxative misuse, diuretic misuse), and the binge eating/purging subtype is used to identify individuals who engaged in regular binge eating, regular purging, or both. DSM-5 will include three major changes to the diagnostic criteria for AN (APA, 2012). First, the A criterion for DSM-IV-TR gives 85% ideal body weight as an example of what might be considered a minimally normal body weight. Although this ideal body weight is only provided to serve as an example, it has commonly been used in both research and clinical practice as a strict cutoff or threshold for body weight when diagnosing AN. DSM-5 will eliminate this example from the A criterion and will require counselors to use more clinical judgment when determining whether an individual meets the underweight criterion for AN. Although the DSM-5 text may include more specific guidelines to help clinicians determine what might be considered minimally normal body weight (e.g., body mass index [BMI], physical symptoms of semistarvation), these parameters have not been identified. Second, the B criterion for AN will be modified to read “intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight” (American Psychiatric Association, 2012b, para. 2). Ultimately, this criterion means that if an individual denies fear of weight gain but regularly engages in behavior (e.g., dietary restriction, fasting, excessive exercise, purging) to prevent or avoid weight gain, that individual would still meet this criterion even if he or she denies an intense fear of gaining weight or becoming fat. Third, the D criterion will be eliminated, which means that amenorrhea or the loss of menstrual cycles will no longer be required for a diagnosis of AN. It is important to note that although amenorrhea will no longer be required for a diagnosis of AN, the loss of menstrual cycles can be used to determine whether an individual is underweight. Thus, assessment of amenorrhea will still be important when using DSM-5 criteria.

The DSM-IV-TR criteria for BN are (a) the presence of binge eating, defined as the consumption of an unusually large amount of food coupled with a subjective sense of loss of control; (b) the presence of compensatory behaviors (i.e., self-induced vomiting, abuse of laxatives or diuretics, excessive exercise, or fasting); (c) the occurrence of both binge eating and compensatory behaviors at least twice per week for the past 3 months; and (d) overevaluation of shape and weight (APA, 2000). Similar to AN, the DSM-IV-TR recognizes two subtypes of BN. The purging subtype identifies individuals who engage in regular purging compensatory behaviors (i.e., self-induced vomiting, abuse of laxatives or diuretics), and the nonpurging subtype identifies individuals who regularly engage in nonpurging compensatory behaviors (i.e., excessive exercise or fasting) but not purging behaviors. Additionally, we should note that in contrast to previous editions of the manual, the DSM-IV-TR does not allow an individual to be diagnosed with two EDs simultaneously. Rather, a diagnosis of AN trumps a diagnosis of BN, meaning that if an individual meets criteria for both AN and BN (e.g., an individual who is below a minimally normal weight, endorses fear of weight gain and overevaluation of shape and weight, who has amenorrhea, and who engages in binge eating and compensatory behaviors at least twice per week for 3 months), that person would be diagnosed with AN, binge eating/purging subtype, rather than BN according to the DSM-IV-TR. Given that the DSM-IV-TR criteria for AN and BN have substantial overlap (e.g., overevaluation of shape and weight), the most fundamental difference between AN and BN was the weight criterion. The DSM-5 criteria for BN will largely remain the same (APA, 2012a); however, they will have two major changes. First, the frequency criterion for binge eating and compensatory behaviors will decrease from twice per week for 3 months to once per week for 3 months; second, BN will no longer include subtypes. The criteria will be the same as those described in the DSM-IV-TR, including the specification that AN trumps BN.

Last, the DSM-IV-TR provides the following examples of clinical presentations that would meet the criteria for EDNOS: (a) All criteria for AN are met, except amenorrhea; (b) all criteria for AN are met except that the individual is at a normal weight; (c) all criteria for BN are met except that the binge eating and compensatory behaviors occur less frequently than twice per week or for a shorter duration than 3 months; (d) regular purging without binge eating; (e) chewing and spitting food out without swallowing and no regular compensatory behaviors; (f) binge eating without the use of compensatory behaviors (i.e., binge eating disorder, or BED; APA, 2000). One of the primary goals for the DSM-5 Eating Disorders Work Group was to address two important problems associated with the EDNOS category. First, as stated earlier, DSM-IV-TR EDNOS is meant to capture a small group of individuals with subthreshold EDs. However, research found that rates of DSM-IV-TR EDNOS were significantly higher than those for DSM-IV-TR AN and BN (e.g., Fairburn et al., 2007; Hoek, 2006). Additionally, the associated psychopathology, psychosocial impairment, treatment response, and medical-suicide risk of DSM-IV-TR EDNOS were comparable to those of DSM-IV-TR AN and BN (e.g., Crow et al., 2009; Fairburn et al., 2007), which suggests that individuals diagnosed with DSM-IV-TR EDNOS may not have been accurately described as having subthreshold symptoms.

The criteria for DSM-5 will reduce the prevalence of EDNOS through several changes (APA, 2012a). First, as described earlier, the criteria for both AN and BN have been broadened (e.g., eliminating the amenorrhea requirement for AN, including behavioral indices of fear of weight gain for AN, reducing the required frequency of binge eating and compensatory behaviors for BN to once per week), with the goal of capturing some individuals who would have been diagnosed with DSM-IV-TR EDNOS. Second, a more dramatic change is that BED, one of the clinical syndromes included as an example of EDNOS, will be formally recognized by DSM-5 as a full-threshold ED (discussed in the paragraphs to follow). Last, DSM-5 EDNOS, which has been renamed feeding and eating conditions not elsewhere classified, describes five specific clinical presentations that could be considered for its diagnosis. These syndromes are (a) atypical AN (all criteria for AN are met except that the client is at or above normal weight), (b) subthreshold BN (all criteria for BN are met except that binge eating, purging, or both occurred less than once per week for 3 months), (c) subthreshold BED (all criteria for BED are met except that binge eating occurred less than once per week for 3 months), (d) purging disorder (regular purging in the absence of binge eating), and (e) night eating syndrome (recurrent night eating associated with distress or functional impairment that is not better accounted for by another medical or psychiatric disorder such as BED). Overall, research has demonstrated that these changes result in a substantial decrease in EDNOS (e.g., Berg et al., 2012; Keel, Brown, Holm-Denoma, & Bodell, 2011).

BED, which is provided as an example of EDNOS in DSM-IV-TR, is not formally recognized as a full-threshold ED in DSM-IV-TR. However, specific criteria for BED are included in Appendix B of the DSM-IV-TR (APA, 2000) for the purpose of encouraging research on the validity of the syndrome. The DSM-IV-TR criteria for BED are (a) the presence of binge eating, defined as the consumption of an unusually large amount of food accompanied by a sense of loss of control over eating during the episode; (b) the occurrence of binge eating at least twice per week for a duration of 6 months; (c) the presence of at least three features associated with binge eating (e.g., eating more rapidly than normal, eating until uncomfortably full, eating large amounts of food when not physically hungry, eating alone because of feeling embarrassed about how much one is eating, and feeling disgusted, depressed, or guilty after eating); (d) significant distress regarding binge eating; and (e) the absence of both AN and BN. As described earlier, the DSM-IV-TR does not allow for the diagnosis of two EDs simultaneously; therefore, the DSM-IV-TR also indicates that a diagnosis of either AN or BN trumps a diagnosis of BED. In DSM-5, BED will be included as a full-threshold ED, and the BED criteria will be modified such that binge eating must occur on average at least once per week for the past 3 months, which is consistent with the frequency and duration criteria for BN (APA, 2012a). Although the DSM-IV-TR and proposed DSM-5 BED criteria do not specify a required weight threshold, epidemiological data have suggested that BED is associated with overweight and obesity (Wonderlich, Gordon, Mitchell, Crosby, & Engel, 2009).

The DSM-5 ED section will also expand to include the following two feeding disorders, both of which are often diagnosed in childhood and were previously described in DSM-IV-TR: (a) pica, a disorder characterized by the eating of non-nutritive and nonfood substances, and (b) rumination disorder, which is characterized by the repeated regurgitation of food that is then rechewed, reswallowed, or spit out (APA, 2012a).

Additionally, DSM-5 will include a new feeding disorder, avoidant/ restrictive food intake disorder, to provide a diagnosis for individuals with significant feeding or eating disturbances other than AN and BN that are not related to concerns about body shape or weight. Although pica, rumination disorder, and avoidant/restrictive food intake disorder will be considered full-threshold EDs in DSM-5, individuals with these disorders are more likely to present to medical clinics than to mental health clinics. The DSM-5 Eating Disorders Work Group also considered including obesity in the Feeding and Eating Disorders section of DSM-5, citing the significant health-related consequences of obesity and the fact that psychiatric disorders (e.g., depression, BED) can lead to weight gain. However, research has overall indicated that obesity is a heterogeneous condition and its etiology is multifaceted (Marcus & Wildes, 2009). Thus, given that little evidence has suggested that obesity is the direct result of mental dysfunction, the work group elected to not include obesity in DSM-5. In sum, the criteria for full-threshold EDs will change substantially from DSM-IV-TR to DSM-5. In this chapter, we provide recommendations and guidelines for the assessment and diagnosis of AN, BN, and BED using the DSM-5 criteria.