1  Classification of Eating Disorders

B. Timothy Walsh, M.D.
Evelyn Attia, M.D.
Robyn Sysko, Ph.D.

DSM-5 was published in the spring of 2013 (American Psychiatric Association 2013). Seven years in the making and almost 20 years since the publication of DSM-IV (American Psychiatric Association 1994), DSM-5 formalized significant changes in the official classification of eating disorders. The two biggest changes were the recognition of binge-eating disorder (BED) and the reconceptualization of feeding disorder of infancy or early childhood as avoidant/restrictive food intake disorder (ARFID). A number of important, but less far-reaching, changes were made to the diagnostic criteria for the other eating disorders. The purpose of this chapter is not only to review these changes, and the background and rationale justifying them, but also to provide a broad overview regarding the value of diagnostic categories. Video 1, “Diagnostic issues in the age of DSM-5,” explores these changes in a roundtable discussion.

Introduction to the DSM Approach

Why Make a Diagnosis?

The thinking of Greek philosophers almost two millennia ago suggested to them that it was wise to define boundaries among phenomena where they naturally occurred, leading to the notion that science should “cleave nature at its joints.” The work of the eighteenth-century Swedish botanist Carl Linnaeus, whose writings are cited as the basis for the distinctions “animal, vegetable, and mineral,” is thought to be an excellent example of the utility of such an approach.

The application of this approach to the understanding of human diseases is of enormous potential value. If successful, it permits the identification of the cause or causes of a disease, eventually yielding major advances in improved knowledge of the pathological mechanisms underlying an illness and in the development of specific treatments targeting the underlying cause or causes. For example, the ability to go beyond the description of a patient’s problem as “fever and a bad cough” to either “pneumonia secondary to infection with the pneumococcus bacterium” or “pneumonia secondary to infection with the influenza virus” is extremely useful for choosing the most effective treatment—an antibiotic for the former or an antiviral agent such as oseltamivir (Tamiflu) for the latter. Unfortunately, it has proven challenging to extend this model to the diagnosis of mental illness.

Diagnosis of Mental Illness

In 1960, Thomas Szasz, in The Myth of Mental Illness (Szasz 1960), argued that traditional psychiatric practice mislabeled individuals who were “disabled by living” as having a mental illness. Although this view has largely been relegated to the history books, there remain major challenges in knowing exactly where to draw the line between widely variable normal human behavior and the patterns of thinking and behaving that are generally conceived as illnesses.

The publication of DSM-III (American Psychiatric Association 1980) heralded a major shift in mainstream psychiatry from attempting to classify psychiatric illnesses based on theories of their etiology to a primarily descriptive approach. DSM-III grappled with the challenge inherent in Szasz’s work: “How should a mental disorder be defined?” The authors of DSM-III and its successors, including DSM-5, recognized that there is no clear, strict, and universally accepted definition of a mental disorder. This is equally true of nonpsychiatric medical disorders; that is, perhaps surprisingly, there is no clear and universally accepted definition of what constitutes a disease (Allison et al. 2008). DSM-5 did not significantly alter the fundamental conceptualization of a mental disorder presented in DSM-III, and after considerable debate, the authors of DSM-5 settled on the following definition:

A mental disorder is a syndrome characterized by clinically significant disturbance in an individual’s cognition, emotion regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning. (American Psychiatric Association 2013, p. 20)

DSM-5 also states that an expectable response “to a common stressor or loss...is not a mental disorder” (p. 20), thereby addressing the concerns of Szasz that socially deviant behavior and conflicts between the individual and society, of themselves, are not mental disorders. Finally, DSM-5 notes that mental disorders are usually associated with impairment of function or distress.

The goal of DSM-III was to provide clear and reliable diagnostic criteria for mental illnesses that would allow both clinicians and researchers to communicate accurately. DSM-III and its successors have largely met that goal. Although the reliability of diagnosis among different clinicians is certainly not perfect, agreement comparable to that of many nonpsychiatric medical diagnoses was achieved. A more ambitious goal of the DSM system beginning with DSM-III was to provide clear and reliable diagnostic criteria that would facilitate the identification of homogeneous groups of patients with identical problems. The hope was that studies of such groups would provide a foundation for the identification of causal factors underlying the illnesses. If almost all individuals with a particular form of depression had very similar symptoms, such as the degree to which they had lost the ability to enjoy life, developed insomnia, and lost their appetite, it would be possible for psychiatrists to distinguish the causes of that specific form of depression from other types of mood disturbance, much as physicians can distinguish between viral and bacterial pneumonia (as mentioned in the preceding subsection).

Problems With the DSM Approach

Unfortunately, except in rare instances, this goal has not been achieved. For example, there are few sharp dividing lines among the varied presentations of mood disturbance, and it increasingly appears that the genetic risks for developing many major psychiatric illnesses are not specific to a single disorder—even one that is very narrowly defined. Rather, multiple genes often exert small but cumulatively important effects for a range of disorders (e.g., Ruderfer et al. 2014). More generally, although many risk factors—environmental, genetic, and developmental—have been described, very few causes of specific mental disorders have been identified. In this regard, mental health continues to lag well behind areas such as cardiology and infectious disease, in which major strides have been made over the last several decades in identifying causative pathways for many disorders, thereby permitting the development of objective methods of diagnostic testing and of targeted treatment interventions.

The strategy employed in DSM-III and its successors also has had several unfortunate consequences. The articulation of many clearly but narrowly defined disorders and the understandable decision not to restrict the number of disorders that could be assigned to an individual have produced a high frequency of comorbidity. Individuals meeting criteria for one disorder often meet criteria for another. For example, many individuals meeting DSM criteria for an eating disorder also meet criteria for a depressive disorder, and current knowledge does not allow one disorder to be considered a result of or secondary to the other. In other words, it is generally difficult to know with certainty that an individual’s bulimia nervosa is best attributed to her major depressive disorder or vice versa, or whether the two are independent.

A similar problem has been the high frequency of residual diagnoses, referred to in DSM-IV as “not otherwise specified” (NOS). Because diagnostic categories are narrowly defined in the DSM system, many individuals with a significant problem do not meet criteria for a specific DSM disorder. In the DSM-IV system, the eating disorders section provided a prime example of this problem. DSM-IV specifically defined only two eating disorders, anorexia nervosa (AN) and bulimia nervosa (BN). All other eating disorders of clinical significance received a formal diagnosis of eating disorder not otherwise specified (EDNOS), which included individuals with symptoms that barely missed the diagnostic threshold for AN or BN, along with individuals who met criteria for BED (a provisional diagnosis in DSM-IV). Despite the goals of DSM, the EDNOS moniker conveyed essentially no information beyond the fact that the individual had described a clinically significant eating problem. In some eating disorder programs, an EDNOS diagnosis was assigned to more than half of the patients presenting for treatment (Fairburn and Bohn 2005)!

Advantages of the DSM Approach

In light of these problems, why should the DSM approach be used at all? The short answer is that the DSM system, notwithstanding its significant limitations, is quite useful in communicating about the problem with the patient, with individuals close to the patient, and with other health care professionals. The DSM system is also useful in undertaking research to describe the development and course of mental disorders and to investigate treatment response. In short, the DSM categories have proven to have substantial clinical utility, even though their definitions are not based on fundamental knowledge of the causes of the disorders.

Path From DSM-IV to DSM-5

History

DSM-IV was published in 1994, 7 years after DSM-III-R (American Psychiatric Association 1987), which itself was published 7 years after the landmark promulgation of DSM-III in 1980. Planning for DSM-5 began in the early years of the new millennium with a series of conferences and edited volumes sponsored by the American Psychiatric Association (APA) to consider new ideas and approaches to the diagnostic system. One prominent example that had a significant impact on the DSM-5 development process was an emphasis on the dimensional nature of virtually all mental disorders (Helzer et al. 2008). This concept was most fully embraced in the proposed revisions of the personality disorders section, which suggested that individuals with such problems should first be characterized as having impairments in several broad areas of personality functioning, such as in developing and maintaining intimate interpersonal relationships, and then described in detail using a number of facets of personality function, such as emotional lability. This creative and carefully considered proposal provoked a storm of criticism from investigators and clinicians concerned about the magnitude of the change from the DSM-IV system and, in the end, was judged by the APA leadership to be too controversial to be officially recognized in DSM-5. The proposed new diagnostic approach for personality disorders is presented in DSM-5 in Section III, “Emerging Measures and Models.” Regardless of the controversy, the dimensional perspective had a pervasive influence on DSM-5, leading, for example, to the incorporation of severity measures for many disorders, including the eating disorders.

Among the early and far-reaching decisions made by DSM-5 leadership was the elimination of the section of DSM-IV titled “Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence.” Several important observations led to this decision. Among them was the fact that many disorders not included in this section of DSM-IV, such as anxiety disorders, mood disorders, and psychotic disorders, are also often recognized during childhood and adolescence. In the years since the publication of DSM-IV, it also became clear that many individuals with disorders listed in that section are first diagnosed later in life, including adults with attention-deficit and disruptive behavior disorders. Therefore, in DSM-5, the disorders previously included in the DSM-IV section on disorders usually first diagnosed in infancy, childhood, or adolescence were redistributed in DSM-5 to other sections, and a developmental perspective was incorporated throughout the text, including in the descriptions of each disorder. Pica, rumination disorder, and feeding disorder of infancy or early childhood joined the DSM-5 eating disorders section. Their inclusion led to the change in the title of this section to “Feeding and Eating Disorders,” underlining the links to the two original sections of DSM-IV.

Approach and Process Leading to DSM-5

Work began in earnest on the eating disorders section of DSM-5 in 20062007 with the appointment of the 12 members of the Eating Disorders Work Group. This group comprised prominent clinical investigators from North America and Europe and included five psychiatrists, five psychologists, a nurse investigator, and a physician specializing in adolescent medicine. The work group continued work through the end of 2012 and achieved consensus on all recommendations regarding changes to the diagnostic criteria for feeding and eating disorders.

The initial review of the diagnostic landscape by the work group indicated that although the existing criteria for eating disorders had some problems, they were not completely “broken.” In other words, the community of investigators and clinicians focused on eating disorders fundamentally agreed about the core diagnostic conceptualization of AN and BN. Furthermore, there was a clear consensus that the clinical features of these two disorders, while overlapping in some important regards, were sufficiently different to warrant their remaining distinct disorders. For example, it was clear that the course, complications, and treatment response of individuals with AN differed substantially from those of individuals with BN, emphasizing the clinical utility of separating the two groups diagnostically.

As noted, the major problem with the DSM-IV system for eating disorders was the unacceptably high frequency of the diagnosis of EDNOS in clinical populations. It was quickly apparent that from a logical perspective, there were only two ways to address this problem: to expand criteria for the existing disorders, allowing “near misses” to meet criteria for one of them, and to recognize new disorders. In the end, the work group recommended both. Several critical limitations restricted the breadth of changes considered. If the expansion of criteria was too radical, individuals now meeting the revised criteria for an existing diagnosis might not share the same core clinical characteristics captured by the original criteria. This could potentially be a major problem because it might invalidate decades of accumulated research and experience on the course, outcome, and treatment response of individuals with a disorder. A related and challenging issue throughout the process was a lack of good data to address the impact of many changes that might be considered. One of the standards employed by the work group was not to make significant changes without being reasonably confident of their impact on clinical utility. Therefore, despite the seeming appeal of a number of potential alterations to the diagnostic criteria, the work group endeavored to avoid recommendations not supported by evidence regarding the impact of the changes.

The first years of the work group’s efforts were devoted to identifying specific possible options for change and to conducting a careful examination not only of existing literature but also of unpublished information in search of answers. Thirteen literature reviews, led by members of the work group, were published in 2009-2010 in the International Journal of Eating Disorders. These reviews were significantly augmented by several conferences jointly supported by the National Institute of Mental Health and the APA, culminating in an edited volume published in 2011 (Striegel-Moore et al. 2011). The work group’s initial recommendations were presented in late 2010 on a Web site devoted to the DSM-5 effort and were discussed and debated at multiple international conferences over the next 3 years. The work group was fortunate to receive extensive comments from investigators and clinicians and from individuals who had experienced or were experiencing eating disorders, which led to important changes in the recommendations. A number of field trials, either sponsored by the APA or carried out by interested investigators who generously shared their results with the work group, provided concrete information on the utility and the problems of the recommended changes.

The final recommendations of the Eating Disorders Work Group were submitted to the DSM-5 Task Force by late 2012. After rigorous review by several internal committees and some minor text editing for consistency, the revised criteria were published in DSM-5 in the spring of 2013 largely as recommended.

Video 1, “Diagnostic issues in the age of DSM-5,” features a round-table discussion with B. Timothy Walsh, M.D., and colleagues involved in changes to feeding and eating disorder diagnoses in DSM-5.

images Video Illustration 1: Diagnostic issues in the age of DSM-5 (8:11)

In the remainder of this chapter, we briefly describe the evolution of the feeding and eating disorders included in DSM-5.

Anorexia Nervosa

A Very Brief History

Although significant eating disturbances have presumably occurred since the dawn of human history, AN was the first to be clearly recognized as a clinical disorder. Richard Morton, in his Treatise of Consumptions, published in 1694, described an 18-year-old girl with what he termed “nervous consumption” (Morton 1694). Because Morton did not have the benefit of DSM, we cannot be certain that this young woman, who went on to die of her disorder, met today’s formal criteria for AN. AN received its name almost 200 years later when, in 1873, Sir William Gull in England coined the term for the problems of three young women whose symptoms would clearly satisfy the DSM-III, DSM-IV, and DSM-5 definitions of this disorder (Gull 1997).

This brief history makes clear that the fundamental presentation and conceptualization of AN have remained impressively stable over centuries. The core features of the disorder are not in dispute. The challenge for DSM has been how best to capture them in a useful but concise set of diagnostic criteria.

DSM-IV to DSM-5

DSM-IV (pp. 544-545) required that individuals meet four criteria to merit a diagnosis of AN. The key features can be summarized as follows:

The work group reviewed these criteria and recommended changes to each. The DSM-5 criteria for AN are presented in Box 1–1, and the succeeding subsections describe the major changes from DSM-IV and the rationale supporting the revised criteria.

Box 1–1. DSM-5 Criteria for Anorexia Nervosa
  1. Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected.
  2. Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.
  3. Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.

Excerpted from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Arlington, VA, American Psychiatric Association, 2013. Used with permission. Copyright © 2013 American Psychiatric Association.

Low Body Weight

The salient physical characteristic of individuals with AN is low body weight. Although the DSM-IV Criterion A captured this feature, there were several problems.

The term refusal suggested that the individual’s reluctance to consume sufficient calories to maintain a normal weight was a conscious and active decision and implied a degree of defiance. Although both of these characteristics are sometimes present, more frequently the basis of the inadequate calorie intake is complex, the individual’s understanding of its persistence is poor, and his or her attitude about the problem is quite variable. Refusal also has a somewhat pejorative tone.

The example provided by DSM-IV in parentheses suggested that a low weight might be defined as one that was less than 85% of that expected, which was ultimately a source of significant confusion and controversy. Although intended only as an example, in many settings it became reified into a rigid rule. In addition, it was unclear what standard should be employed for the determination of the “expected” weight.

The DSM-5 Eating Disorders Work Group recommended that although the concept of low body weight was fundamental to AN, the wording of Criterion A should be substantially altered. The term refusal was eliminated in favor of a straightforward description of the behavior: “restriction of energy intake relative to requirements.” The choice of energy intake as opposed to the more specific food intake reflected the work group’s desire to make the definition broadly applicable, even to the very rare instances in which the individual’s primary source of calorie intake was parenteral (e.g., via a gastric feeding tube or an intravenous line). The term “relative to requirements” encompasses situations in which the individual’s caloric intake is statistically normal but inadequate based on unusual requirements, such as intense exercise.

To avoid the confusion that accompanied the inclusion of the example of “85% of expected” in DSM-IV, no numerical guidelines are provided within DSM-5 Criterion A; however, the text of DSM-5 reviews the diagnostic features in two paragraphs with detailed descriptions of standards that can be employed to assist the crucial judgment about whether an individual’s weight is “significantly low.” In the end, this judgment is made by the clinician on the basis of all the information available.

Fear of Gaining Weight

A small but significant fraction of individuals exhibiting other core characteristics of AN deny that they are afraid of gaining weight (Wolk et al. 2005). However, their overt behavior—classically, the steadfast avoidance of high-calorie foods and reluctance to consume foods outside a very narrow range—appears to belie their assertion. Therefore, in DSM-5, the phrase “persistent behavior that interferes with weight gain” was added to the DSM-IV Criterion B to include such presentations within full-threshold DSM-5 AN.

Distortion of Body Image

The work group’s only concern about Criterion C focused on a single word, denial. This term might imply some underlying intrapsychic mechanism, which was not the intent. Therefore, the work group recommended that this term be changed to “persistent lack of recognition,” which was thought to offer a more explicit description of the phenomenon.

Amenorrhea

The greatest change to the DSM-IV criteria for AN was the elimination of Criterion D, which had required amenorrhea. This decision was based on two observations. First, the DSM-IV criterion included a number of exceptions to this criterion, such as being male or being a woman who was taking oral contraceptives. Therefore, in practice, this criterion was often waived. Second, a literature review on this topic documented that there were a number of descriptions of women who met all the other criteria for AN but reported some menstrual activity (Attia and Roberto 2009). Therefore, to allow such individuals to receive the diagnosis of AN rather than EDNOS, the work group deleted this criterion.

The DSM-5 text, however, emphasizes that amenorrhea is a common physiological disturbance associated with AN, and its presence provides additional support for the diagnosis.

Bulimia Nervosa

A Very Brief History

The syndrome of BN was first clearly described and named in 1979 in a landmark paper by Professor Gerald Russell, a major figure in the eating disorders field at that time (Russell 1979). His clear summary of the symptoms of 30 patients captured the essential features of this disorder. DSM-III, published in 1980, included criteria for the syndrome, which was called simply “bulimia.” In 1987, DSM-III-R refined those criteria and renamed the disorder “bulimia nervosa” in accordance with Russell. Only minor changes were made to the DSM-III-R criteria in DSM-IV and DSM-5 (presented in Box 1–2).

Box 1–2. DSM-5 Criteria for Bulimia Nervosa
  1. Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:
    1. Eating, in a discrete period of time (e.g., within any 2-hour period), an amount of food that is definitely larger than what most individuals would eat in a similar period of time under similar circumstances.
    2. A sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating).
  2. Recurrent inappropriate compensatory behaviors in order to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, or other medications; fasting; or excessive exercise.
  3. The binge eating and inappropriate compensatory behaviors both occur, on average, at least once a week for 3 months.
  4. Self-evaluation is unduly influenced by body shape and weight.
  5. The disturbance does not occur exclusively during episodes of anorexia nervosa.

Excerpted from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Arlington, VA, American Psychiatric Association, 2013. Used with permission. Copyright © 2013 American Psychiatric Association.

DSM-IV to DSM-5

The DSM-IV criteria, closely mirroring those of DSM-III-R, required that individuals engage in both binge eating and inappropriate methods to avoid weight gain, such as self-induced vomiting; that both behaviors occur, on average, at least twice a week over the prior 3 months; and that shape or weight exert an undue influence on self-evaluation.

In the development of DSM-5, no data suggested the need for major changes to the DSM-IV criteria for BN. Only two, relatively small, alterations were suggested by the work group. A literature review (Wilson and Sysko 2009) found limited evidence to support the twice-weekly binge-eating and compensatory behavior frequency requirement; a small number of individuals presented for clinical care who met all the DSM-IV criteria but reported binge eating and purging only once a week. Therefore, in line with the effort to reduce the use of EDNOS, the work group recommended that the frequency criterion (Criterion C) be changed to “at least once a week.” Another literature review found that the scheme in DSM-IV to classify individuals with BN as having either the purging or the nonpurging type was of limited utility and was frequently not employed (van Hoeken et al. 2009). Therefore, in DSM-5, the DSM-IV requirement that individuals be assigned to either the purging or the nonpurging type has been eliminated.

Binge-Eating Disorder

A Very Brief History

In 1959, the late Albert Stunkard, an eminent psychiatrist who was among the first mental health professionals to think carefully about the problems of individuals with obesity, published a paper on eating patterns among obese individuals that provided the first clear description of binge eating. These observations received surprisingly little attention until the development of DSM-IV was under way. Spearheaded by Robert Spitzer, the leader of the development of DSM-III, a major effort was made to develop criteria to capture the essential features of binge eating without the purging characteristic of BN. These efforts resulted in the first criteria for BED. Although there was significant interest in this disorder’s being formally recognized in DSM-IV, in the end it was felt that sufficient data about its clinical characteristics, course, and outcome were unavailable, and the criteria were therefore included in DSM-IV in an appendix providing criteria sets for further study.

DSM-IV to DSM-5

A critical question considered by the DSM-5 work group concerning BED was whether to recommend that this disorder be formally recognized. To address this question, Stephen Wonderlich led a comprehensive review of the literature on BED that had emerged since DSM-IV (Wonderlich et al. 2009). This review documented the publication of over 1,000 articles in the medical literature since the preliminary criteria for BED were promulgated. These articles amply documented the breadth of clinical interest in this syndrome and provided detailed information on the characteristics of individuals meeting the provisional criteria. In particular, the data indicated that individuals with BED as defined by DSM-IV demonstrated an objective disturbance in eating behavior during meals observed in laboratory settings and had an increased frequency of mood and anxiety disturbance compared to similarly overweight or obese individuals without BED. In addition, there were tentative indications that, to achieve the best clinical outcomes, individuals with BED should receive specific treatment interventions. For these reasons, the work group recommended that BED be formally recognized in DSM-5. After careful review by the DSM-5 Task Force, this recommendation was accepted (see Box 1–3 for criteria). Not surprisingly, this change contributed to a significant reduction in the frequency of use of EDNOS.

Box 1–3. DSM-5 Criteria for Binge-Eating Disorder
  1. Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:
    1. Eating, in a discrete period of time (e.g., within any 2-hour period), an amount of food that is definitely larger than what most people would eat in a similar period of time under similar circumstances.
    2. A sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating).
  2. The binge-eating episodes are associated with three (or more) of the following:
    1. Eating much more rapidly than normal.
    2. Eating until feeling uncomfortably full.
    3. Eating large amounts of food when not feeling physically hungry.
    4. Eating alone because of feeling embarrassed by how much one is eating.
    5. Feeling disgusted with oneself, depressed, or very guilty afterward.
  3. Marked distress regarding binge eating is present.
  4. The binge eating occurs, on average, at least once a week for 3 months.
  5. The binge eating is not associated with the recurrent use of inappropriate compensatory behavior as in bulimia nervosa and does not occur exclusively during the course of bulimia nervosa or anorexia nervosa.

Excerpted from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Arlington, VA, American Psychiatric Association, 2013. Used with permission. Copyright © 2013 American Psychiatric Association.

The work group also considered whether the draft criteria for the diagnosis of BED should be modified in any way. The available literature supported only a single small change. Specifically, to make the frequency requirement for BED identical to that for BN, the DSM-IV criterion was changed from a minimum of binge episodes occurring on at least 2 days per week, on average, over the last 6 months to a minimum of at least one episode of binge eating per week, on average, over the last 3 months (Wilson and Sysko 2009).

Avoidant/Restrictive Food Intake Disorder

As described in the section “Path From DSM-IV to DSM-5,” an early and important decision in the development of DSM-5 was to combine, in a single section, the syndromes previously listed among the eating disorders and the feeding and eating disorders of infancy or early childhood sections of DSM-IV. The greatest challenge in doing so was presented by the DSM-IV diagnosis of feeding disorder of infancy or early childhood.

This diagnosis made its first appearance in the DSM system in DSM-IV and was intended to capture presentations of infants and young children who, for some reason, perhaps related to difficult interactions with their caregivers or other developmental issues, were not growing as they should. Members of the DSM-5 Eating Disorders Work Group performed a literature review to examine this diagnosis in detail and uncovered a number of problematic issues (Bryant-Waugh et al. 2010). Clinicians appeared to rarely use this diagnosis in practice, and virtually no scholarly research had focused on feeding disorder of infancy or early childhood. Furthermore, the work group became aware that there were a number of clinically significant eating problems particularly affecting young people that were not covered by this or any other DSM-IV diagnosis. Therefore, after extensive consultation with clinicians caring for young people with a range of eating problems, the work group recommended that the existing diagnosis of feeding disorder of infancy or early childhood be expanded and retitled avoidant/restrictive food intake disorder (ARFID). Studies initiated by a group of adolescent medicine specialists interested in eating disorders were generously made available to the work group during the final stages of DSM-5 development. Data from these studies indicated that in specialist practices focusing on eating problems of young people, the criteria for ARFID (presented in Box 1–4) successfully captured a significant number of individuals who did not meet criteria for any other eating disorder (Fisher et al. 2014; Ornstein et al. 2013).

Box 1–4. DSM-5 Criteria for Avoidant/Restrictive Food Intake Disorder
  1. An eating or feeding disturbance (e.g., apparent lack of interest in eating or food; avoidance based on the sensory characteristics of food; concern about aversive consequences of eating) as manifested by persistent failure to meet appropriate nutritional and/or energy needs associated with one (or more) of the following:
    1. Significant weight loss (or failure to achieve expected weight gain or faltering growth in children).
    2. Significant nutritional deficiency.
    3. Dependence on enteral feeding or oral nutritional supplements.
    4. Marked interference with psychosocial functioning.
  2. The disturbance is not better explained by lack of available food or by an associated culturally sanctioned practice.
  3. The eating disturbance does not occur exclusively during the course of anorexia nervosa or bulimia nervosa, and there is no evidence of a disturbance in the way in which one’s body weight or shape is experienced.
  4. The eating disturbance is not attributable to a concurrent medical condition or not better explained by another mental disorder. When the eating disturbance occurs in the context of another condition or disorder, the severity of the eating disturbance exceeds that routinely associated with the condition or disorder and warrants additional clinical attention.

Excerpted from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Arlington, VA, American Psychiatric Association, 2013. Used with permission. Copyright © 2013 American Psychiatric Association.

The final criteria for ARFID intentionally encompass a range of presentations. Individuals meeting the DSM-IV criteria for feeding disorder of infancy or early childhood are included in ARFID. In addition, individuals who have a problem with food intake associated with other problems may also meet criteria for this disorder. Common examples are individuals who have experienced a frightening or particularly difficult but transient gastrointestinal problem, such as an episode of acute vomiting after eating, and subsequently severely restrict their food intake to avoid another such episode. Another presentation is that of individuals who avoid foods of a certain texture or color. Minor variants of such problems occur commonly, especially among children, but the criteria for ARFID and the text of DSM-5 emphasize that the diagnosis should be assigned only in situations in which the food restriction leads to a clinically significant nutritional disturbance or to a serious impairment in psychosocial functioning. It is also critical to distinguish ARFID from AN. Although both disorders are associated with serious nutritional problems, individuals with AN, unlike those with ARFID, describe a marked overconcern about shape and weight and an intense fear of gaining weight or becoming obese.

Pica

Pica refers to persistent consumption of nonnutritive, nonfood items that is inappropriate for the individual’s developmental age. Pica may occur in association with a number of medical conditions, including during normal pregnancy. The disorder should not be assigned if it is occurring in the context of another mental or medical condition or disorder unless it is so severe that it warrants additional clinical attention.

The only changes recommended to the DSM-IV criteria for pica were minor alterations to the wording of the criteria for clarification and to make clear that the disorder could be assigned to the behavior of adolescents and adults as well as children. The DSM-5 criteria for pica are presented in Box 1–5.

Box 1–5. DSM-5 Criteria for Pica
  1. Persistent eating of nonnutritive, nonfood substances over a period of at least 1 month.
  2. The eating of nonnutritive, nonfood substances is inappropriate to the developmental level of the individual.
  3. The eating behavior is not part of a culturally supported or socially normative practice.
  4. If the eating behavior occurs in the context of another mental disorder (e.g., intellectual disability [intellectual developmental disorder], autism spectrum disorder, schizophrenia) or medical condition (including pregnancy), it is sufficiently severe to warrant additional clinical attention.

Excerpted from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Arlington, VA, American Psychiatric Association, 2013. Used with permission. Copyright © 2013 American Psychiatric Association.

Rumination Disorder

Rumination refers to the persistent, repeated regurgitation of food that has already been swallowed. Relatively little is known about this phenomenon. Rumination occurs among some individuals with AN and BN, but in such cases, an additional diagnosis of rumination disorder is not assigned.

As in the case of pica, the only changes recommended to the DSM-IV criteria for rumination disorder were for the purpose of clarification and to make clear that this disorder can be assigned to individuals across the life span. The DSM-5 criteria for rumination disorder are presented in Box 1–6.

Box 1–6. DSM-5 Criteria for Rumination Disorder
  1. Repeated regurgitation of food over a period of at least 1 month. Regurgitated food may be re-chewed, re-swallowed, or spit out.
  2. The repeated regurgitation is not attributable to an associated gastrointestinal or other medical condition (e.g., gastroesophageal reflux, pyloric stenosis).
  3. The eating disturbance does not occur exclusively during the course of anorexia nervosa, bulimia nervosa, binge-eating disorder, or avoidant/restrictive food intake disorder.
  4. If the symptoms occur in the context of another mental disorder (e.g., intellectual disability [intellectual developmental disorder] or another neurodevelopmental disorder), they are sufficiently severe to warrant additional clinical attention.

Excerpted from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Arlington, VA, American Psychiatric Association, 2013. Used with permission. Copyright © 2013 American Psychiatric Association.

Conclusion

Virtually all of the diagnostic categories used to describe mental disorders, including the feeding and eating disorders, are based on descriptions of salient psychological and behavioral features but not on a detailed understanding of the underlying causes of the disorders. Nevertheless, the categories are of substantial clinical utility in facilitating accurate communication among patients, clinicians, and investigators. Changes to diagnostic criteria for feeding and eating disorders in DSM-5 should significantly reduce the use of residual categories (“not otherwise specified”), encourage continued research, including about ARFID and BED, and, it is hoped, provide a useful foundation for improved care of patients.

Key Clinical Points

References

Allison DB, Downey M, Atkinson RL, et al: Obesity as a disease: a white paper on evidence and arguments commissioned by the Council of the Obesity Society. Obesity (Silver Spring) 16(6):1161-1177, 2008 18464753

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition. Washington, DC, American Psychiatric Association, 1980

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition, Revised. Washington, DC, American Psychiatric Association, 1987

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 4th Edition. Washington, DC, American Psychiatric Association, 1994

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. Arlington, VA, American Psychiatric Association, 2013

Attia E, Roberto CA: Should amenorrhea be a diagnostic criterion for anorexia nervosa? Int J Eat Disord 42(7):581-589, 2009 19621464

Bryant-Waugh R, Markham L, Kreipe RE, et al: Feeding and eating disorders in childhood. Int J Eat Disord 43(2):98-111, 2010 20063374

Fairburn CG, Bohn K: Eating disorder NOS (EDNOS): an example of the troublesome “not otherwise specified” (NOS) category in DSM-IV. Behav Res Ther 43(6):691-701, 2005 15890163

Fisher MM, Rosen DS, Ornstein RM, et al: Characteristics of avoidant/restrictive food intake disorder in children and adolescents: a “new disorder” in DSM-5. J Adolesc Health 55(1):49-52, 2014 24506978

Gull WW: Anorexia nervosa (apepsia hysterica, anorexia hysterica). 1868. Obes Res 5(5):498-502, 1997 9385628

Helzer JE, Kraemer HC, Krueger RF, et al: Dimensional Approaches in Diagnostic Classification. Arlington, VA, American Psychiatric Association, 2008

Morton R: Phthisiologia, or, A Treatise of Consumptions. London, Smith & Walford, 1694

Ornstein RM, Rosen DS, Mammel KA, et al: Distribution of eating disorders in children and adolescents using the proposed DSM-5 criteria for feeding and eating disorders. J Adolesc Health 53(2):303-305, 2013 23684215

Ruderfer DM, Fanous AH, Ripke S, et al; Schizophrenia Working Group of Psychiatric Genomics Consortium; Bipolar Disorder Working Group of Psychiatric Genomics Consortium; Cross-Disorder Working Group of Psychiatric Genomics Consortium: Polygenic dissection of diagnosis and clinical dimensions of bipolar disorder and schizophrenia. Mol Psychiatry 19(9):1017-1024, 2014 24280982

Russell G: Bulimia nervosa: an ominous variant of anorexia nervosa. Psychol Med 9(3):429-448, 1979 482466

Striegel-Moore RH, Wonderlich SA, Walsh BT, et al (eds): Developing an Evidence-Based Classification of Eating Disorders: Scientific Findings for DSM-5. Arlington, VA, American Psychiatric Association, 2011

Szasz TS: The myth of mental illness. Am Psychol 15(2):113-118, 1960

van Hoeken D, Veling W, Sinke S, et al: The validity and utility of subtyping bulimia nervosa. Int J Eat Disord 42(7):595-602, 2009 19621467

Wilson GT, Sysko R: Frequency of binge eating episodes in bulimia nervosa and binge eating disorder: diagnostic considerations. Int J Eat Disord 42(7):603-610, 2009 19610014

Wolk SL, Loeb KL, Walsh BT: Assessment of patients with anorexia nervosa: interview versus self-report. Int J Eat Disord 37(2):92-99, 2005 15732073

Wonderlich SA, Gordon KH, Mitchell JE, et al: The validity and clinical utility of binge eating disorder. Int J Eat Disord 42(8):687-705, 2009 19621466