Behavior Emotion Therapy System and You: Co-Design and Evaluation of a Mental Health Chatbot and Digital Human for Mild to Moderate Anxiety in Healthy Participants

Journal article, 2025

Background: Co-design is a collaborative approach involving end users, stakeholders, and designers in creating digital tools for health care. This study focuses on the co-design and evaluation of Behavior, Emotion, Therapy System, and You (BETSY), a mental health chatbot and digital human for mild to moderate anxiety. Objective: This study aims to develop and evaluate BETSY through a co-design process involving potential users. Methods: The study used a mixed-methods approach across 3 phases. Phase 1 involved recruiting 87 volunteer participants through social media for initial end-user requirements. Phase 2 focused on the design process based on end-user requirements using the expertise of 10 stakeholders in health care and health service user. Phase 3 evaluated the 2 prototyped interfaces (a text-only chatbot and a voice-activated digital human chatbot) with 45 healthy volunteers. Results: For phase 1, 61% (n=51) of participants had previous experience with chatbots and 86% expressed a willingness or potential willingness to use a chatbot for mental health support. Thematic analysis in phase 2 revealed key user preferences for a personalized, nonjudgmental chatbot with a clear identity and a focus on empathy. Privacy concerns and the need for clear interaction guidelines were highlighted. In phase 3, the users showed a strong preference for discussing anxiety related to work, relationships, and health. Both text-only and voice-activated digital human users considered BETSY valuable for managing mild to moderate anxiety and providing self-help exercises. Conclusions: The co-design process yielded valuable insights for developing BETSY. While users recognized its potential as an accessible first step before seeking professional help, they also identified areas for improvement, including more nuanced conversation capabilities and a broader range of exercises. BETSY’s potential as a screening tool for health care was consistently acknowledged, suggesting its capability for alleviation of health care system burdens.