Eating Disorder Chatbot Optimization

Not Applicable

Not yet recruiting

• Conditions: Eating Disorders

• Registration Number: NCT07218302
• Lead Sponsor: Washington University School of Medicine

Brief Summary

The purpose of this study is to optimize an automated digital chatbot intervention for adults with clinical or subclinical eating disorders.

Detailed Description

Eating disorders (EDs) are common-affecting an estimated 10% of individuals in their lifetimes-and have disabling consequences being associated with high psychiatric comorbidity, impairment, and mortality. Despite this, less than 20% of individuals with an ED ever receive treatment. When individuals do seek treatment, many are not evidence-based and come with high costs and burden on the healthcare system. One solution to this is a chatbot intervention that is evidence-based, affordable, and accessible for people with EDs. This project will assess four candidate components of a cognitive behavioral therapy (CBT)-based chatbot to determine the optimal chatbot package. CBT is the recommended first-line treatment for EDs, yet there is no research to date on which components are most effective or needed for meaningful change in ED psychopathology. In this study the intervention will be divided into four components targeting: (1) over-evaluation of weight and shape; (2) dietary restraint; (3) emotion dysregulation; and (4) resisting urges to binge. The investigators will recruit 800 adults with a binge/purge-type ED who are not currently in treatment and randomly assign participants to one of 16 experimental conditions (each combination from 1 to all 4 components) or the waitlist-control group. Participants will be assessed on changes in ED psychopathology, ED behavior frequencies, comorbid symptoms (i.e., depression, anxiety), and clinical impairment at 1-, 2-, and 6-months following randomization. An optimized package of these candidate components that is most effective, while remaining efficient, will be identified using multiphase optimization strategy (MOST). The investigators' established relationships with industry and non-profit partners will ensure this optimized package has high potential for scalability and dissemination into the community.

Study Timeline

• Status Verified: 2025-10
• Study First Submitted: 2025-10-15
• Study First Submitted QC: 2025-10-15
• Study First Posted: 2025-10-20
• Last Update Submitted: 2025-10-20
• Last Update Posted: 2025-10-22
• Study Start: 2026-03-01
• Primary Completion: 2029-07-31
• Study Completion: 2029-07-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 800

Inclusion Criteria

• 18+ years old
• Owns a smartphone
• Speaks English
• US resident
• Screens for a clinical or subclinical eating disorder
• Low suicidality
• Not currently in treatment for an eating disorder
• Does not have a medical condition or take medications that impact appetite/weight
• Not currently pregnant

Exclusion Criteria

• Below 18 years of age
• Does not own a smartphone
• Does not speak English
• Lives outside the US
• Screens as: at risk for an eating disorder, anorexia nervosa, atypical anorexia nervosa, avoidant/restrictive food intake disorder, or not at risk for an ED
• High suicidality
• In treatment for an eating disorder
• Has a medical condition or takes medication(s) that impact appetite/weight
• Currently pregnant

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: FACTORIAL

Primary Outcome Measures

Name	Time	Method
ED psychopathology; ED Examination-Questionnaire (EDE-Q)	6 months	The EDE-Q is a 28-item inventory derived from an ED diagnostic interview, which asks self-reported concerns with weight and shape, and engagement in ED behaviors, over the last 28 days. Each item is scored from 0-6, with 0 being "No days" and 6 being "Every day". An average is taken of all items participants respond to for a total global score (with possible scores ranging from 0 to 6), where higher scores indicate greater symptomology.

Secondary Outcome Measures

Name	Time	Method
ED behaviors from the EDE-Q; Muscle Building Subscale from the Eating Pathology Symptoms Inventory (EPSI)	6 months	The EDE-Q will also be used to gauge self-reported engagement in ED behaviors. Additionally, the EPSI Muscle Building subscale will be used which is a 5-item questionnaire that asks self-reported frequency of muscle building behaviors and attitudes over the last 28 days. Each item is scored from 0 ("Never") to 4 ("Very Often"). Subscale score is calculated by summing items participants respond to (scores may range from 0 to 20), and higher scores indicate greater symptomology.
Depression; Patient Health Questionnaire (PHQ-9)	6 months	The PHQ-9 is a 9-item scale asking about self-reported depressive symptoms and suicidality over the past two weeks. All items are scored from 0 ("Not at all") to 3 ("Nearly every day"). Items participants respond to are summed (possible scores ranging from 0 to 27), and higher scores indicate greater symptomology.
Anxiety; Generalized Anxiety Disorder (GAD-7)	6 months	The GAD-7 is a 7-item scale assessing self-reported symptoms of anxiety over the past two weeks. All items are scored from 0 ("Not at all") to 3 ("Nearly every day"). Items participants respond to are summed (possible scores ranging from 0 to 21), and higher scores indicate greater symptomology.
Clinical Impairment; Clinical Impairment Assessment (CIA)	6 months	The CIA is a 16-item measure that assesses self-reported impairment, or impact on one's life, resulting from eating, weight, or shape in the last 28 days. All items are scores from 0 ("Not at all") to 3 ("A lot"). Items participants respond to are summed (possible scores ranging from 0 to 48), and higher scores indicate greater impairment.

Trial Locations

Locations (1)

Washington University in St. Louis; 🇺🇸 St Louis, Missouri, United States