Module 5 – Feeding Disorders

3rd edition as of August 2022

Module Overview

In Module 5, we will discuss matters related to feeding disorders to include their clinical presentation, prevalence, comorbidity, etiology, assessment, and treatment options. Our discussion will include pica, rumination disorder, and avoidant/restrictive food intake disorder. Be sure you refer to Modules 1-3 for explanations of key terms (Module 1), an overview of the various models to explain psychopathology (Module 2), and descriptions of the various therapies (Module 3).

Module Outline

• 5.1. Clinical Presentation and DSM-5-TR Criteria
• 5.2. Prevalence and Comorbidity
• 5.3. Etiology
• 5.4. Assessment and Treatment

Module Learning Outcomes

• Describe how pica, rumination disorder, and avoidant/restrictive food intake disorder present.
• Describe the prevalence of the feeding disorders.
• Describe the etiology of the feeding disorders.
• Describe how the feeding disorders are assessed, diagnosed, and treated.

5.1. Clinical Presentation and DSM-5-TR Criteria

Section Learning Objectives

• Contrast feeding and eating disorders.
• Describe the presentation and associated features of pica.
• Describe the presentation and associated features of rumination disorder.
• Describe the presentation and associated features of avoidant/restrictive food intake disorder.

5.1.1. Overview of Feeding and Eating Disorders

According to the DSM-5-TR, feeding and eating disorders, “…are characterized by a persistent disturbance of eating or eating-related behavior that results in altered consumption or absorption of food and that significantly impairs physical health or psychosocial functioning” (APA, 2022, pg. 371). These disorders used to be considered two different areas of concern in previous editions of the DSM, but with the DSM-5 (and now 5-TR), they have been combined into one category (APA, 2013 and 2022). For our purposes, we will separate them out into two separate modules – one on feeding disorders and one on eating disorders.

So, what makes them different from one another? First, feeding disorders are simply that, concern with how one feeds and consumes food, typically in young children and/or individuals with other developmental concerns (e.g., intellectual delays). Second, an eating disorder is related more to eating habits, rather than feeding concerns, whether it be under or overeating, and occurs more frequently in typically developing (meaning no developmental or cognitive delays) individuals from childhood or adolescence to adulthood. As noted earlier, our discussion in this module will focus on pica, rumination disorder, and avoidant/restrictive food intake disorder (the feeding disorders) and later we will discuss anorexia, bulimia, and binge eating disorders (the eating disorders; in Module 16).

5.1.2. Pica

Pica is the act of eating items that are not food on a regular or recurring basis over a period of at least one month. These nonnutritive, nonfood substances could include grass, chalk, dirt, paper, hair, soap, wool, paint, gum, pebbles, coal, ash, or starch, to name a few. Pica can impair physical functioning but any impairment in social functioning usually occurs in conjunction with other disorders. The behavior is inappropriate to the developmental level of the child, so it should not be diagnosed before age 2 to exclude developmentally normal mouthing of objects leading to ingestion, typical of infants. Also, the behavior should not be part of a culturally supported or socially normative practice such as ingesting a particular grass for medicinal or spiritual purposes (APA, 2022). Pica is not often associated with specific biological abnormalities, though deficiencies in vitamins and minerals such as iron and zinc, have been reported.

Pica may occur more frequently in disorders such as autism spectrum disorder (or other mental health disorders); however, a clinician must be careful to ensure that the act of eating nonfood items is to a higher degree than would be expected if another disorder is present. For example, if a child regularly attempts to eat grass because they like the oral stimulation of it, and are diagnosed with autism spectrum disorder, a clinician must determine if the individual is attempting to ingest a nonfood item, or if they are trying to orally stimulate. If the individual is only trying to orally stimulate, they would not be diagnosed with pica.

5.1.3. Rumination Disorder

Rumination disorder is the frequent act of regurgitating food over a period of at least 1 month with no medical explanation such as gastroesophageal reflux and in the absence of a body-image/weight-related reason such as anorexia, bulimia, and binge-eating disorder. An individual may rechew and then eject the food from the mouth or re-swallow (APA, 2022).

Functional consequences of rumination disorder include growth delay due to malnutrition secondary to repeated regurgitation. Though the onset of the disorder can occur at any time during life, when it begins in infancy, the age at onset is between ages 3 and 12 months, and it can be fatal.

5.1.4. Avoidant/Restrictive Food Intake Disorder

Avoidant/restrictive food intake disorder is a new disorder to the DSM 5 (APA, 2013) and replaces and extends the DSM-IV diagnosis of feeding disorder of infancy or early childhood (Norris & Katzman, 2015). It is an eating or feeding disturbance associated with at least one of the following: 1) significant weight loss, 2) significant nutritional deficiency, 3) dependence on enteral feeding or oral nutrition supplements, and 4) marked interference with psychosocial functioning. The disturbance is not better explained due to a lack of available food or a culturally sanctioned practice.

The food avoidance or restriction may occur due to the sensory characteristics of qualities of food such as its appearance, color, smell, texture, taste, or temperature. It may occur due to a conditioned negative response associated with food intake following, or in anticipation of, an aversive event such as choking, repeated vomiting, or a traumatic procedure. And for some, the food avoidance or restriction occurs due to a lack of interest in eating or food.

5.2. Prevalence and Comorbidity

Section Learning Objectives

• Describe the prevalence of pica, rumination disorder, and avoidant/restrictive food intake disorder.
• Describe comorbid disorders with pica, rumination disorder, and avoidant/restrictive food intake disorder.

5.2.1. Pica

Limited data suggests that the prevalence of pica is around 5% of school-age children and a third of pregnant women engage in pica, especially if they have food insecurity (APA, 2022; Murray, Thomas, Hinz, Munsch, & Hilbert, 2018). Some studies indicate that pica is more common in males than females (El-Nemer, Alian, Salah-Eldin, Khalil; 2014) whereas others do not show a significant difference between genders (APA, 2022; Murray et al., 2018). A worldwide meta-analysis showed a prevalence of 28% during pregnancy and/or the postpartum period (APA, 2022).

Autism spectrum disorder and intellectual developmental disorder (intellectual disability) are the two most common comorbid diagnoses. Less common are schizophrenia and OCD. Pica may also be comorbid with trichotillomania (hair-pulling disorder), excoriation (skin-picking) disorder, and avoidant/restrictive food intake disorder.

5.2.2. Rumination Disorder

Limited European data suggests a prevalence of 1% to 2% of grade-school-age children. Rumination disorder also occurs more frequently in individuals with an intellectual disability (Olden, 2001). It can occur in the context of a concurrent medical condition or another mental disorder such as generalized anxiety disorder.

5.2.3 Avoidant/Restrictive Food Intake Disorder

Again, prevalence rates are largely unknown. A study in Australia reported a frequency of 0.3% among individuals aged 15 years and up. Avoidant/restrictive food intake disorder is more common in children with autism spectrum disorder and when so, has a male predominance. This is possibly due to sensory concerns and rigidity that leads to children having very specific preferences for foods. Children may actively refuse to eat many foods due to texture aversions. When autism spectrum disorder is not comorbid, the disorder occurs about equally between males and females.

As mentioned, autism spectrum disorder is a common comorbid disorder. Other neurodevelopmental disorders may be highly comorbid such as ADHD, intellectual development disorder (intellectual disability), anxiety disorders, and OCD (APA, 2022).

5.3. Etiology

Section Learning Objectives

• Describe various biological, behavioral, and sociocultural causes of feeding disorders.

5.3.1. Pica

Pica is commonly associated with an iron deficiency. It is theorized that extremely low iron levels lead to individuals consuming non-perishable foods that, although not nutritious, may contain high iron content. El-Nnemer and colleagues (2014) confirmed that a large portion of children exhibiting pica in their study had low levels of zinc, hemoglobin, iron, and ferritin. They also found that other factors such as low nourishment and low socioeconomic status were risk factors for pica for the individuals in their study. Neglectful caregiving, lack of supervision, and developmental delay may also be risk factors for the development of pica (APA, 2022).

5.3.2. Rumination Disorder

Information related to rumination disorder etiology is limited. However, like pica, neglectful caregiving, a difficult parent-child relationship, lack of stimulation, and early life stress may be important risk factors to consider (APA, 2022).

5.3.3 Avoidant/Restrictive Food Intake Disorder

Various factors may contribute to the development of avoidant/restrictive food intake disorder. Parent-child interactions may be particularly important to consider. How a parent approaches feeding the child is important. It may be that they do not present and feed the child ‘properly.’ Additionally, when the child rejects the food, the parent may become frustrated and discouraged. This may further increase tension during feeding and lead to increased restriction and avoidance. Moreover, parental psychopathology, such as mothers with eating disorders, (APA, 2022) and neglect/abuse may exacerbate the above interactions as well.

Children with avoidant/restrictive food intake disorder often have families with high rates of anxiety (Cooper et al., 20014).  Gastrointestinal or gastroesophageal disorders may lead to children highly restricting their food as well (Burklow et al., 1998).

5.4. Assessment and Treatment

Section Learning Objectives

• Describe assessment methods for feeding disorders.
• Describe treatment options for feeding disorders.

5.4.1. General Assessment of Feeding-related Concerns

Often, assessment begins with parent/caregiver reports during interviews. A psychologist will likely conduct a thorough interview to obtain detailed information about what the child eats or does not eat, if the behaviors improve or worsen at any point, and any other related concerns. They may also ask questions related to the parent’s feeding practices with the child. Additionally, a thorough medical examination to rule out medical conditions causing these atypical feeding concerns is necessary. Given the need for both a psychological and medical screening, assessments for these disorders often occur in specialized feeding clinics where a multidisciplinary team can conduct thorough screenings. These screenings may include blood draws for nutrition checks, gastrointestinal and gastroesophageal scopes, swallow studies (to rule out any structural issues with feeding movements), and observation of parent-child feeding sessions.

5.4.2. Therapy for Feeding-related Concerns

Similar to assessment, treatment frequently, but not always, occurs in a feeding clinic. Because these disorders occur more often in the developmentally delayed, treatment is very likely to take place in other settings. It is important to point out that because avoidant/restrictive food intake disorder is highly comorbid with autism spectrum disorder due to sensory concerns, feeding therapy may also be incorporated into a child’s ABA goals (Applied Behavior Analysis (ABA); this will be discussed in the module on autism spectrum disorder), and thus, be conducted outside of a feeding clinic setting.

In general, nutritional supplementation may be used to protect a child’s health as well as potentially mitigate the need for certain behaviors. For example, if an individual has extremely low levels of iron, iron supplements may be given to increase the individual’s iron levels, and thus, reduce pica behaviors. If there are structural or gastro-related reasons for the disorders, interventions related to medical, occupational (in the sense of occupational therapy, not vocational terms), or other specialized fields of expertise will be utilized.

     5.4.2.1 Pica. Behavioral interventions are the primary modality of treatment for pica (Call, Simmons, Lomas Mevers, & Alvarez, 2015; Sturmey & Williams, 2016). For example, a technique within behavioral interventions that appears beneficial is differential reinforcement (Slocum, Mehrkam, Peters, & Vollmer, 2017). Briefly, differential reinforcement is when we attempt to get rid of undesirable or problem behaviors (in this case, pica) by using positive reinforcement (e.g., providing a reward of some sort) of desirable behaviors. For example, Differential Reinforcement of Alternative Behavior (DRA) is useful in reducing pica. DRA is when we reinforce the desired behavior and do not reinforce undesirable behavior. Hence, the desired behavior increases, and the undesirable behavior decreases to the point of extinction. The main goal of DRA is to increase a desired behavior such as eating an edible food item or even discarding the non-edible item. The therapist might praise the individual, offer a tangible reward, etc. when an individual selects an edible food item or discards a non-edible item.

     5.4.2.2 Rumination disorder. Again, behavioral interventions are heavily utilized. A functional behavioral assessment is often implemented first to help understand the reason for the behaviors. A functional behavioral assessment is when we closely scrutinize the antecedents and consequences of behaviors to see what affects the occurrence or nonoccurrence of a desired or problem behavior. Through functional behavioral assessments, research indicates that rumination is automatically reinforced by sensory stimulation; that is, rumination provides a sensory stimulus that is reinforcing (Luiselli, 2015). This was more common than rumination occurring due to an attempt to gain attention, gain a desirable toy/object, or to escape from something. As such, interventions may attempt to replace the sensory stimulation of regurgitation of food/rumination by introducing either food or liquid continuously, on a fixed schedule, for a period of time following the target meal (Luiselli, 2015). This provides a replacement sensory stimulation (through foods or liquids) for an extended period of time. Because the sensory stimulation is considered to be desirable by the individual, it serves as reinforcement. Since the reinforcement (the food or liquid) is provided for a period, and does not require a particular behavior from the individual for the individual to receive the reinforcer, it is considered noncontingent. As such, noncontingent reinforcers are being utilized. It should be noted that, the foods and liquids that are used as noncontingent reinforcers must be food or liquids that are desired or preferred by the individual. The idea of this type of therapy is to break the automatic reinforcement of rumination by providing expected reinforcing experiences in an alternative way.

     5.4.2.3 Avoidant/restrictive food intake disorder. Interventions may focus on similar behavioral principals outlined above (Sharp, Burrell, & Jaquess, 2014). Children may be rewarded with contingent attention, such positive reinforcement, when the child eats a previously rejected food (Werle, Murphy, & Budd, 1993). This may occur in a clinic and/or at home. Essentially, behavioral principals are applied to increase food tolerance. Efforts for parents to learn how to implement these behavioral strategies around meals shows promising improvement for the child (Sharp, Burrell, & Jaquess, 2014; Najdowski, Wallace, Reagon, Penrod, Higbee, & Tarbox, 2010). The parent is providing food exposure for the child and rewarding the child for success. Again, strategies such as DRA, previously described, become useful here. These interventions may occur in the context of a feeding clinic; however, they may also occur at home, or in the context of a child’s ongoing ABA therapy.

Consider that child-parent interactions may also strongly impact the development and maintenance of avoidant/restrictive food intake disorder. As such, carefully exploring the feeding patterns during mealtime between the parent and child is imperative. If irritability or frustration perpetuate the feeding difficulty, interventions to help increase the parent’s awareness and provide support for the parent may be utilized. The parent might even observe a feeding therapist implement a feeding session with the child. In this situation, the therapist can model helpful strategies, how to deal with irritability from the child, etc.

Module Recap

In Module 5, we discussed feeding disorders including pica, rumination disorder, and avoidant/restrictive food intake disorder. We discussed how these disorders present. In addition, we clarified the epidemiology, comorbidity, and etiology of each disorder. Finally, we discussed how these disorders are assessed and potential treatment options for each.

In our next module, we will continue to discuss disorders of infancy and early childhood by reviewing elimination disorders.

3rd edition