Chatbot Intervention Effects on Belief Updating in Anhedonia

Effects of a Chatbot-Based Intervention on Valence-Dependent Belief Updating and Expectancy Bias for Life Events in Individuals With Anhedonia

The main aim of the present study is to investigate the effects of a Motivational Interviewing-based artificial intelligence chatbot on belief updating in college students with elevated levels of depression and anhedonia by combining a randomized active-control intervention design with pre- and post-intervention behavioral belief updating task assessments.

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Behavioral: MI Chatbot Interaction; Behavioral: Active Control Chatbot Interaction

Detailed Description

Anhedonia represents a core characteristic of depression and is characterized by reduced experience of pleasure. It is closely related to decreased motivation, altered reward processing, changes in affective responsiveness, and alterations in intrinsic brain network function. Anhedonia is not specifically targeted by currently available pharmacological interventions. Initial evidence indicates that an increased willingness to change and implementation of change in daily life can alleviate anhedonia.

The present study aims to examine whether a Motivational Interviewing-based AI chatbot can lead to changes in belief updating in college students with elevated anhedonia and depressive symptoms. Belief updating is included because anhedonia and depressive symptoms may be associated with biased or inflexible use of new information, which may influence future expectations, motivation, and engagement in rewarding activities. The belief updating task allows the study to examine how participants revise their expectations after receiving new information. To this end, eligible participants with a total score of 23.5 or higher on the Snaith-Hamilton Pleasure Scale and a score of 14 or higher on the Beck Depression Inventory will undergo a randomized, between-subjects, active-control intervention study. Participants will be assigned to either a Motivational Interviewing-based chatbot group or an active control chatbot group for 1 week. Pre- and post-intervention assessments will include self-report questionnaires and a behavioral belief updating task to examine psychological and behavioral effects of the intervention.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Benjamin Becker, Dr; Phone Number: (852) 3917-5097; Email: bbecker@hku.hk

Study Locations

• China
  • Sichuan
    • Chengdu, Sichuan, China
      • Recruiting
      • University of Electronic Science and Technology of China

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 18-40 years
• Right-handed
• Normal or corrected normal visual acuity
• Participants must show elevated anhedonia and depressive symptoms at screening, defined as a total score of 23.5 or higher on the Snaith-Hamilton Pleasure Scale and a score of 14 or higher on the Beck Depression Inventory

Exclusion Criteria:

• History of major central nervous system disorders, such as epilepsy, traumatic brain injury, stroke, or brain tumors.
• History of severe mental illness, including schizophrenia spectrum disorders, bipolar disorder, or other psychotic disorders.
• History of substance or alcohol use disorder or substance or alcohol misuse within the past 12 months that may affect study participation or outcome assessment.
• Individuals currently at high risk of suicide, severe self-harm, or experiencing an acute psychiatric crisis.
• Individuals who are currently using psychiatric medications or have undergone psychotherapy within the past 4 weeks that may significantly affect mood, motivation, or reward processing.
• Severe vision or hearing impairments that cannot be corrected and would interfere with task performance.
• Contraindications to MRI scanning, including metallic implants, pacemakers, severe claustrophobia, or other conditions incompatible with MRI.
• Pregnancy or breastfeeding.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Motivational Interviewing-based AI chatbot group; Motivational Interviewing-based AI chatbot intervention	Behavioral: MI Chatbot Interaction; The experimental chatbot is designed to use principles of Motivational Interviewing to support participants in exploring their personal values, motivation for change, and daily behavioral goals related to pleasure, engagement, and reward-seeking. During the intervention period, participants will interact with the chatbot regularly through brief text-based conversations. The chatbot will provide empathic, non-judgmental responses, encourage reflection on current difficulties, and help participants identify small, feasible actions that may increase daily engagement and positive experiences. It will not provide diagnosis, crisis counseling, or medical treatment.
Active Comparator: Active control chatbot group; Active control nature-story chatbot intervention	Behavioral: Active Control Chatbot Interaction; Participants will interact with a chatbot matched in format and frequency of use. This chatbot will provide neutral nature-related stories or general natural history content. It will be designed to maintain participant engagement while avoiding therapeutic techniques, motivational interviewing strategies, behavioral activation guidance, or personalized mental health advice. This active control condition will help control for nonspecific effects of chatbot interaction, attention, expectancy, and digital engagement.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Valence-dependent belief updating bias	Belief updating magnitude will be calculated separately for positive and negative information conditions in the belief updating task before and after the intervention. Updating magnitude will be quantified based on changes in probability estimates before and after the presentation of new information. The difference in updating magnitude between positive and negative information conditions will be calculated and compared from baseline to post-intervention.	Baseline before the first chatbot interaction and Week 1 after completion of the chatbot intervention.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Expectancy bias for life events	Before receiving base-rate information or new information, participants will provide initial probability estimates for positive and negative life events at baseline and post-intervention. Mean initial estimates will be calculated separately for the two event types, and pre-to-post changes in the difference between positive and negative event estimates will be compared.	Baseline before the first chatbot interaction and Week 1 after completion of the chatbot intervention

Collaborators and Investigators

• Sponsor: University of Electronic Science and Technology of China

Study record dates

Study Major Dates

• Study Start (Estimated): June 20, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: June 17, 2026
• First Submitted That Met QC Criteria: June 22, 2026
• First Posted (Actual): June 23, 2026

Study Record Updates

• Last Update Posted (Actual): June 23, 2026
• Last Update Submitted That Met QC Criteria: June 22, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: fMRI; AI Interaction
• Other Study ID Numbers: BAM_lab_MI_05

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Corresponding individual level data will be made available upon request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No