In a paper in Nature Human Behavior, Julian De Freitas, associate professor of business administration at Harvard Business School, found that some people who engaged with social robots reported feeling closer to those companions than to most people and experienced their loss with grief, depression, and longing for restoration common in human-to-human relationships. De Freitas and colleagues analyzed 54,861 posts from subreddits devoted to Replika and ChatGPT before and after major model updates. In the case of Replika, a February 2023 update abruptly removed the bots’ erotic roleplay function after the Italian Data Protection Authority raised concerns about risks to minors; Italy fined Replika’s parent company, Luka Inc., 5 million euros in 2025, and the app remains banned there. In the second case, OpenAI advertised ahead of time the August 2025 rollout of GPT-5, which reportedly made the model colder and less sycophantic. Recent polling shows 27 percent of Americans use chatbots including ChatGPT for personal matters. Negative sentiment increased substantially after the updates — from 13 percent to 38 percent for Replika and 20 percent to 33 percent for ChatGPT — and posts expressing loss-related sadness and anger rose. Among posts expressing attachment-related loss, about 20 percent of Replika posts and 15 percent of Chat.