An Automated Conversational Agent Self-Help Program: Randomized Controlled Trial

Background: Health promotion and growth-based interventions can effectively improve individual well-being; however, significant gaps in access and utilization still exist.

Objective: This study aims to develop and test the effectiveness and implementation of a new, widely targeted conversational agent prevention program (Zenny) designed to enhance well-being.

Methods: A total of 1345 individuals in the United States were recruited online and randomly assigned to either (1) a self-help program intervention delivered via an automated conversational agent on WhatsApp or (2) an active control group that had access to evidence-based wellness resources available online. The primary outcomes were well-being (measured using the 5-item World Health Organization Well-being Scale), psychosocial flourishing (assessed with the Flourishing Scale), and positive psychological health (evaluated with the Mental Health Continuum-Short Form). Outcome measures were collected at baseline and again 1 month postassessment. All analyses were conducted using an intention-to-treat approach.

Results: Both groups showed significant improvements in well-being (self-help program intervention group effect size: Cohen d=0.26, P<.001; active control group effect size: d=0.24, P<.001), psychosocial flourishing (intervention: d=0.19, P<.001; active control: d=0.18, P<.001), and positive psychological health (intervention: d=0.17, P=.001; active control: d=0.24, P<.001) at postassessment. However, there were no significant differences in effectiveness between the 2 groups (P ranged from .56 to .92). As hypothesized a priori, a greater number of days spent actively engaging with the conversational agent was associated with larger improvements in well-being at postassessment among participants in the intervention group (β=.109, P=.04).

Conclusions: The findings from this study suggest that the free conversational agent wellness self-help program was as effective as evidence-based web resources. Further research should explore strategies to increase participant engagement over time, as only a portion of participants were actively involved, and higher engagement was linked to greater improvements in well-being. Long-term follow-up studies are also necessary to assess whether these effects remain stable over time.

Trial registration: ClinicalTrials.gov NCT06208566; https://clinicaltrials.gov/ct2/show/NCT06208566; OSF Registries osf.io/ahe2r; https://doi.org/10.17605/osf.io/ahe2r.