Cognitive-behavioral Therapy vs. Nutrition Counseling for Avoidant/Restrictive Food Intake Disorder Part II

• Cognitive-Behavioral Therapy for Avoidance Restrictive Food Intake Disorder (CBT-AR) (Behavioral): CBT-AR is a four-stage modular treatment for ARFID delivered by a mental health clinician. The four stages include: 1) Psychoeducation and early change; 2) Treatment planning; 3) Addressing maintaining mechanisms; and 4) Relapse prevention. For participants ages 10-15 years, patients/guardians attend the sessions. For patients ages 16 and up, the therapy is individual.
• Nutrition Counseling for Avoidant/Restrictive Food Intake Disorder (Behavioral): Nutrition counseling will be provided by skilled registered dietitians at the MGH Translational and Clinical Research Center (TCRC). Sessions focus on the foods necessary for a healthy diet, how to meet nutritional needs, how to incorporate healthy exercise, and support for making these changes. For participants ages 10-15 years, patients/guardians attend the sessions. For patients ages 16 and up, the therapy is individual.

Primary outcomes

• Pica, ARFID, and Rumination Disorder Interview [Change from baseline measured at Pre-Treatment to Mid-Treatment to 15 weeks of treatment measured at Post-Treatment.]: A semi-structured clinical interview assessing the symptoms and severity of Pica, ARFID, and Rumination Disorder. This interview is used to determine the presence and severity of each ARFID profile. Scores for each severity measure are assessed on a scale from 0 to 6, with higher scores indicating greater severity.
• Pica, ARFID, and Rumination Disorder ARFID Questionnaire [Change from baseline measured at Pre-Treatment to Mid-Treatment to 15 weeks of treatment measured at Post-Treatment.]: A 32-item revised version of the Pica, ARFID, and Rumination Disorder Interview used to assess ARFID severity and presence of Pica or Rumination Disorder. Each item is assessed on a scale from 0 to 6, with higher scores indicating greater severity.

Secondary outcomes

• General Nutrition Knowledge Questionnaire [Completed at Pre-Treatment Assessment (Baseline/Week 0), Mid-Treatment Assessment (Week 8 +/- 2 sessions), and Post-Treatment Assessment (Week 16 up to Week 19)]: A revised version of the General Nutrition Knowledge Questionnaire (GNKQ) used to evaluate knowledge of nutrition. Scores are gathered through a series of multiple-choice questions. The lowest score possible is 0, indicating low knowledge of nutrition, and the highest score possible is 14, indicating high knowledge of nutrition.
• 4-Day Food Record [Completed at Pre-Treatment Assessment (Baseline/Week 0), Mid-Treatment Assessment (Week 8 +/- 2 sessions), and Post-Treatment Assessment (Week 16 up to Week 19)]: A record of participant diet for four days prior to the Pre-Treatment Assessment and for another four days prior to the Post-Treatment Assessment. Dietary information is calculated from the recorded foods.

Sex: All, ages: 10 Years to 18 Years

Inclusion Criteria:

* Males and Females ages 10-18 years old
* Current ARFID assessed via Feeding and Eating Disorders Model from the "Enhanced" Structured Interview for DSM-5 (SCID-5)
* Normal TSH or free T4 levels to rule out thyroid disease as cause of symptoms inclusionary for randomization
* Negative celiac screening panel indicating no active celiac disease as cause of symptoms inclusionary for randomization
* Fluency and literacy in English

Exclusion Criteria:

* Patient requires weight restoration treatment (e.g., < 5th percentile of BMI, height, or weight for sex and age; patient has fallen off individual growth trajectory; patient's medical providers have recommended weight restoration) such that 15 sessions of CBT-AR is not appropriate
* Pregnancy, breastfeeding, or recent initiation/cessation of estrogen-containing systemic contraceptives within 8 weeks of the pre-treatment study visit (as these could impact neuroimaging)
* Current/history of psychosis via Mini-International Neuropsychiatric Interview child/adolescent version (MINI KID)
* Substance/alcohol use disorder (active within the past month) via MINI KID
* Medical instability requiring inpatient care according to the American Psychiatric Association 2006 treatment guidelines for eating disorders
* Laboratory abnormalities indicating a need for higher level of care (assessed by complete blood count and comprehensive metabolic panel) exclusionary for randomization
* Complete lack of oral intake (suggesting a need for inpatient care)
* Tube feeding (suggesting a need for tube weaning) Significant weight/shape concern-motivating eating pathology as evidenced by a global Eating Disorders Examination Questionnaire (EDE-Q) score greater than 4
* Active suicidal ideation with intent or plan via the 5-item Self-Injurious Thoughts and Behaviors Interview-Revised (SITBI-R)
* Contraindications to MRI
* History of major gastrointestinal tract surgery or serious medical condition (e.g., cancer)
* Medical history of intellectual disability
* Illiteracy