Exposure-Based CBT for Avoidant/Restrictive Food Intake in Functional Dyspepsia

The purpose of this study is to conduct a randomized controlled trial (RCT) of a cognitive-behavioral treatment (CBT) compared to usual care as the control with adults with functional dyspepsia who also meet criteria for avoidant/restrictive food intake disorder (ARFID). Participants randomized into the CBT group will receive eight 1-hour sessions delivered weekly via the MGH-approved secure video platform Enterprise Zoom while the usual care group will be allowed to continue with treatment they are already receiving at the time of randomization. Participants in the usual care group will be offered CBT after study participation. We will determine the feasibility and acceptability of the CBT and explore changes in clinical outcomes and preliminary mechanisms.

Inclusion criteria

• Age at least 18 years at screening visit
• Rome IV Functional Dyspepsia post-prandial distress type (with or without epigastric pain syndrome)
• Negative upper endoscopy or upper radiographic GI series to rule out structural/organic cause for FD
• Avoidant/Restrictive Food Intake Disorder (ARFID) diagnosis (by the Structured Clinical Interview for DSM-5; SCID-5 at Screening visit)
• ≥5% weight loss from weight after functional dyspepsia symptom onset (at Screening visit)
• Stable for outpatient care (based on the American Psychiatric Association Practice Guideline for the Treatment of Patients with Eating Disorders)
• No previous history of CBT for functional dyspepsia or ARFID
• Computer/internet webcam access
• Fluency in English
• Stable dose for 30 days if on any medication

Exclusion criteria

• Inability to provide informed consent
• Presence of other conditions that could explain the patient's symptoms by chart:

Pyloric or intestinal obstruction (by EGD, UGI, or Abdominal CT) Active H.pylori infection (by CLO test or stool antigen test) Active inflammatory bowel disease Eosinophilic gastroenteritis or eosinophilic esophagitis Acute renal failure Chronic renal failure (serum creatinine >3 mg/dL) and/or on hemodialysis or peritoneal dialysis Acute liver failure Any acute gastrointestinal process Any plausible structural or metabolic causes Heartburn as predominant symptom History of peptic ulcer

• Symptom resolution with antisecretory therapy (PPI use for other reasons that did not resolve FD symptoms will be allowed)
• History of gastrointestinal tract surgery (including gastrectomy, gastric bypass surgery, and small or large bowel resection)
• History of any serious medical condition (e.g., cancer)
• Use of narcotic analgesics greater than three days per week
• Current pregnancy or breastfeeding within the last 8 weeks
• Uncontrolled diabetes (indicated by HbA1c ≥7%) by chart
• Intellectual disability by history
• Current substance/alcohol use disorder within the past month
• Current/history of psychosis (by Mini-International Neuropsychiatric Interview (MINI-Screen)
• Current mania (by Mini-International Neuropsychiatric Interview (MINI-Screen) (defined as any manic episodes within the past 12 months)
• Active suicidal ideation (by MINI-Screen)
• Psychiatric disorder that would warrant independent attention (by Mini-International - Neuropsychiatric Interview (MINI-Screen))
• Current enteral or parenteral feeding
• Plans to initiate another psychotherapy or pregnancy in the concurrent study period