Co-occurrence of avoidant/restrictive food intake disorder and traditional eating psychopathology

To the Editor:

Avoidant/restrictive food intake disorder (ARFID) is a feeding/eating disorder introduced in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) characterized by inadequate volume and/or variety of food intake.¹ ARFID represents an expansion of the prior DSM-IV disorder “Feeding Disorder of Early Childhood” that can be diagnosed across the lifespan.^1,2 DSM-5 clearly states that ARFID cannot be diagnosed in the context of significant shape/weight concerns and associated behaviors.¹ However, our clinical team has observed multiple instances in which adolescent girls have presented with frank ARFID and simultaneously reported, or ultimately developed, traditional eating-disorder psychopathology. The following two cases are representative of the most common presentations of this diagnostic overlap that we have seen. We discuss possible reasons for this overlap and suggest two revisions to DSM criteria that may help in treatment planning for this unexpected comorbidity. Each patient provided written consent for their case to be included.

Case 1.

A 12-year-old girl choked on a piece of bread, developed an intense fear of choking, and abruptly lost a significant amount of weight (12 lbs), falling off her growth curve. She met DSM-5 criteria for ARFID via A1 (i.e., significant weight loss precipitated by fear of choking). Her declining weight alarmed her pediatrician, prompting development of a treatment plan for weight re-gain. During treatment, she initially re-gained a small amount of weight, but reached a plateau and began refusing high-calorie foods. She developed de novo body checking (e.g., using a measuring tape to check her waist circumference) and avoidance (e.g., wearing baggy clothing), yet remained fearful of choking and unable to eat previously preferred foods.

Case 2.

A 16-year-old girl had a long history of selective eating (consuming no fruits or vegetables) since childhood. Due to her limited diet, she had a vitamin D deficiency and her providers felt she was at risk for iron deficiency. She felt guilty that her food restrictions impacted peer and family activities (e.g., she struggled to eat at restaurants, family holidays, or while traveling). To prevent embarrassment, she avoided eating with others. She met ARFID criteria via A2 (risk for nutritional deficiency via a blood test) and A4 (psychosocial impairment). Because she ate preferred foods only when alone, she often went long periods (e.g., the entire school day) without eating, leading her to eat large quantities of preferred foods when at home. She reported feeling out of control and eating rapidly during these twice-weekly binge-eating episodes. The high-calorie, high-sugar, and high-fat nature of her preferred foods resulted in weight gain and she was extremely dissatisfied with her appearance. Subsequently, she attempted to follow strict dietary rules to limit her already restricted dietary range in an effort to lose weight.³

Discussion

We hypothesize that—rather than being completely distinct disorders as suggested in DSM-5— a combination of neurobiological factors and developmental stressors may engender traditional eating-disorder psychopathology in adolescents with ARFID. ARFID may (1) share endophenotypes with symptoms of other eating disorders, simultaneously increasing risk for all forms of disordered eating and/or (2) ARFID symptoms themselves or accommodation to ARFID symptoms may precipitate additional eating pathology.

(1). Some individuals with ARFID who have heightened sensory sensitivity to taste, appearance, or texture report extreme disgust responses to certain foods.² Picky eating in childhood is considered a prospective risk factor for later AN development.⁴ Perhaps individuals with ARFID who also exhibit disgust sensitivity are at risk for generalizing disgust responses to their body shape, particularly during key life-transitions like puberty. Early evidence shows that individuals with ARFID have a heavy reliance on detail-level processing, a cognitive thinking style marked by rigidity that may underlie inflexibility in dietary variety.⁵ Additionally, detail-level cognitive processing is implicated in the pathogenesis of disordered eating, particularly in AN.⁶ Poor interoceptive awareness is also a risk factor for the development of eating disorders and is associated with difficulty interpreting gastrointestinal stimuli.⁷ Irregular eating patterns in ARFID may be related to disrupted appetite awareness via dysregulated hunger and satiety cues.²

(2). Adolescence is marked by increasing significance of complex peer relationships and adolescents tend to want to be more similar to their friends.⁸ Many ARFID symptoms such as weight changes and irregular eating habits are obvious. While symptoms such as weight loss may be praised, others such as weight gain or reliance on preferred/safe foods, may be teased. Weight loss and weight-related teasing are considered risk factors for the development of eating-disorder psychopathology.^7,9 ARFID eating can also be associated with significant changes in family functioning.² Overprotection, high maternal anxiety, difficult meals, and conflict about food/eating increase risk for eating disorder development in longitudinal studies.^7,10

Research suggests eating-disorder recovery is most likely if treatment is initiated soon after illness onset and treatment outcomes for anorexia nervosa are best for adolescents.¹¹ Failure to achieve full recovery during adolescence from eating/feeding disturbances puts individuals at risk for serious, possibly long-lasting, medical complications (e.g., structural and functional brain abnormalities, bone loss).^2,12 Our team provides Cognitive-Behavioral Therapy for ARFID (CBT-AR) to individuals with ARFID, which includes several techniques (e.g., regular eating, weighing, food fear hierarchies) common to empirically-supported therapies for traditional eating disorders.² In our clinical practice we have seen some cases in which supplementing these common techniques with psychoeducation targeting weight/shape (e.g., weight redistribution occurring first in the abdomen; appropriate mirror use) from Cognitive Behavior Therapy and Eating Disorders (CBT-E)¹³ is sufficient for elimination of weight/shape-motivated behaviors (e.g., body checking, dietary rules). However, research is needed to describe different presentations of overlapping ARIFD and eating disorder psychopathology and to support specific recommendations depending on presentation.

To better understand the prevalence and nature of this overlap, we recommend ongoing assessment for traditional eating-disorder psychopathology in adolescents who present with ARFID symptoms and assessing for ARFID symptoms in those who present with traditional eating disorders. In Table 1 we propose two possible options in which the diagnostic criteria for feeding/eating disorders could be revised, to address the diagnostic dilemmas typified by Case 1 and Case 2 and guide treatment development. Option 1 would allow ARFID and eating-disorder psychopathology to be diagnosed simultaneously with one diagnosis identified as primary, potentially determined by the order of symptom development or current symptom severity. In contrast, option 2 would clarify that the development of weight/shape-motivated behaviors should always represent diagnostic crossover. Currently a diagnosis of AN or BN would trump a diagnosis of ARFID, but option 2 would clarify that a diagnosis of BED or OSFED would also be a trump. Treatment outcome research as well as studies exploring common traits between feeding and eating disorders and the impact of developmental factors on illness trajectory would help inform if either option is an appropriate revision to DSM criteria.

Table 1.

Two Possible Diagnostic Options for Case 1 and Case 2

	DSM-5 criteria met for ARFID1	DSM-5 criteria met for a traditional eating disorder1	Diagnostic option 1: Allow for co-occurrence of feeding and eating disorders	Diagnostic option 2: Clarify diagnostic crossover with clear trump rules
Case 1	Acute food avoidance following a choking episode resulting in significant fear of choking and subsequent weight loss of greater than 10 lbs and crossing from 75th to 50th percentile	Significant weight loss, intense fear of gaining weight, and undue influence of body weight/shape on self-evaluation as evidenced by self-measuring of waist and skipping meals/snacks with high calorie items	ARFID + OSFED: Case 1 met all criteria for DSM-5 AN-R except reaching significantly low weight. Thus, she met criteria for OSFED, and in particular, atypical AN.1 DSM-5 does not currently allow for the concurrent diagnoses of ARFID and atypical AN, although the patient met criteria for both.	OSFED
Case 2	Long-standing selective eating (avoidance of all fruits, animal proteins, and vegetables) due to sensory sensitivity resulting psychosocial impairment, vitamin D deficiency, and risk for iron deficiency.3	Long periods of fasting (8 or more hours) followed by recurrent binge eating, characterized by eating alone from embarrassment, feeling guilty/disgusted afterwards, eating rapidly, and distress around binge eating 3	ARFID + BED Case 2 met criteria for DSM-5 BED. DSM-5 does not currently allow for the concurrent diagnoses of ARFID and BED1, although the patient met criteria for both.3	BED

Note: ARFID = avoidant/restrictive food intake disorder; DSM-5 = Diagnostic and Statistical Manual of Mental Disorders 5^th edition; BMI = body mass index; AN-R: anorexia nervosa-restricting subtype; AN = anorexia nervosa; OSFED = other specified feeding or eating disorder; BED: binge eating disorder.

In our clinical experience, it is not unusual for adolescents who present with frank ARFID to simultaneously report or subsequently develop traditional eating-disorder psychopathology. Exploring the prevalence and severity of eating disorder psychopathology in ARFID, delineating illness trajectories (including diagnostic crossover from ARFID to traditional eating disorders and vice-versa), examining shared biological vulnerabilities, and how/when to address this co-occurrence in treatment represent important areas for research. Findings will be relevant in informing potential revisions to diagnostic classification.