Background: The characteristics, application, and effectiveness of chatbots in improving the mental health of young people have yet to be confirmed through systematic review and meta‐analysis. Aim: This systematic review aims to evaluate the effectiveness of chatbot‐delivered interventions for improving mental health among young people, identify factors influencing effectiveness, and examine feasibility and acceptability. Methods: To identify eligible interventional studies, we systematically searched 11 databases and search engines covering a publication period of January 2014 to September 2024. Meta‐analyses and subgroup analyses were performed on randomized controlled trials to investigate the effectiveness of chatbot‐delivered interventions and potential influencing factors. Narrative syntheses were conducted to summarize the feasibility and acceptability of these interventions in all the included studies. Results: We identified 29 eligible interventional studies, 13 of which were randomized controlled trials. The meta‐analysis indicated that chatbot‐delivered interventions significantly reduced distress (Hedge's g = −0.28, 95% CI [−0.46, −0.10]), but did not have a significant effect on psychological well‐being (Hedge's g = 0.13, 95% CI [−0.16, 0.41]). The observed treatment effects were influenced by factors including sample type, delivery platform, interaction mode, and response generation approach. Overall, this review demonstrates that chatbot‐delivered interventions were feasible and acceptable. Linking Evidence to Action: This review demonstrated that chatbot‐delivered interventions had positive effects on psychological distress among young people. Chatbot‐delivered interventions have the potential to supplement existing mental health services provided by multidisciplinary healthcare professionals. Future recommendations include using instant messenger platforms for delivery, enhancing chatbots with multiple communication methods to improve interaction quality, and refining language processing, accuracy, privacy, and security measures.

Background: There exists a notable disparity in meeting the psychological health needs of young people through available services and resources. Chatbots, enabling synchronous interactions between humans and digital devices, hold promise as a technology to assist in filling the treatment gap. This study aims to systematically evaluate the effectiveness, feasibility, and acceptability of chatbot-delivered interventions for young people’s psychological health. Methods: We systematically searched 11 databases and search engines covering the publication period from January 2014 to September 2024 to identify eligible interventional studies. Meta-analyses and subgroup analyses were performed on randomized controlled trials to investigate the effectiveness of chatbot-delivered interventions and potential influencing factors. Narrative syntheses were conducted to summarize the feasibility and acceptability of these interventions in all the included studies. Results: We identified 29 eligible interventional studies, of which 13 were randomized controlled trials. The meta-analysis indicated that chatbot-delivered interventions significantly reduced psychological distress, but did not have a significant effect on psychological well-being. The treatment effects observed were influenced by factors including sample type, delivery platform, interaction mode, and response generation approach. Overall, this systematic review demonstrates that chatbot-delivered interventions were feasible and acceptable. Conclusions: Chatbot-delivered interventions have the potential to supplement existing mental health services provided by healthcare professionals.

Background: Expressed emotion (EE) is a robust predictor of relapse in individuals with schizophrenia-spectrum disorders. However, the evidence on this relationship has not been fully examined in individuals with bipolar disorder (BD). This systematic review was conducted to provide updated evidence on the association between EE and relapse in BD. Methods: A systematic search was conducted in seven databases and two registries from inception to 29 December 2025. The Joanna Briggs Institute's (JBI) critical appraisal checklists were used to assess the risk of bias in the included studies. The review process was conducted independently by two reviewers, with consensus for each step achieved through consultation with a third reviewer. A narrative synthesis was performed to categorise the findings, with particular focus on the impact of global EE and its subdomains on relapse in BD. Results: Of the 2963 records identified, seven studies were included in this review. The majority of studies were rated as having a low risk of bias. The narrative synthesis indicates that high EE is significantly associated with an increased risk of relapse in BD, particularly for depressive episodes, and is linked to critical comments and emotional over-involvement, two key subdomains of EE. Conclusions: This review provides evidence of a potential association between high EE, its subdomains, and relapse in BD. These preliminary findings contribute to the development of family-based interventions for BD and highlight the need for larger-scale, longitudinal prospective cohort studies to further clarify this relationship. Registration: The study has been registered on https://www.crd.york.ac.uk/prospero/ (registration number: CRD42025632303; registration link: https://www.crd.york.ac.uk/PROSPERO/view/CRD42025632303).