Interesting meta analysis of evidence here concluded: chat agents significantly reduced symptoms of depression and distress.
Li H, Zhang R, Lee YC, Kraut RE, Mohr DC. Systematic review and meta-analysis of AI-based conversational agents for promoting mental health and well-being. NPJ Digit Med. 2023 Dec 19;6(1):236. doi: 10.1038/s41746-023-00979-5. PMID: 38114588; PMCID: PMC10730549.