Evaluation of a CBT-Based Program for Mental Health in the General Population During the COVID-19 Pandemic: A Stepped-Care Approach Using a Chatbot and Digitized Group Intervention.

Background: The COVID-19 pandemic exposed a substantial portion of society to multiple stressors, while access to mental health care was limited. To address this, we introduced a digital stepped-care program rooted in cognitive-behavioral therapy (CBT) principles, aiming to alleviate mental health distress among the general public seeking help. Methods: The program comprises a 4-week digital application using "Aury" the chatbot, followed by an optional 6-week online group session for those still symptomatic. A 4-week waiting period separated these steps. Participants entered based on self-identified mental health concerns. Interventions addressed prevalent pandemic mental health issues: sleep disturbances, anxiety, depression, worry/rumination, interpersonal issues, and resource mobilization. Outcomes focused on depressive, anxiety, and somatic symptoms, assessed by the Patient Health Questionnaire (PHQ). Results: Of the 1261 initial participants, postchatbot results (N = 142) indicated small to medium effects (d = 0.412 to d = 0.523). Those finishing the entire program (N = 41) saw substantial symptom decline with medium to large effects (d = 0.757 to d = 0.818). No shifts were seen in the waiting phase. At follow-up 6 months after baseline, both groups-those who only used the chatbot (N = 60; d = 0.284 to d = 0.416) and those who completed the entire program (N = 27; d = 0.854 to d = 0.926)-showed sustained symptom reduction. Comparing groups that received no intervention, used the chatbot only, and completed the entire program, we observed a dose-response effect. Conclusions: This resource-efficient and adaptable digital approach effectively reduced pandemic-induced mental health issues, indicating its potential in crisis periods with limited health resources. Randomized controlled trials are recommended for further validation. Trial Registration: Clinical Trial Registry identifier: DRKS00023220.