The Dark Side of AI Companionship: A Cautionary Study.

A Nature Human Behaviour study of 1,131 Character.AI users who donated chat logs finds that companionship-motivated use correlates with worse well-being, with heavier use and deeper self-disclosure predicting poorer outcomes, especially for people with smaller social circles, while light, casual use shows no harm.

Transcript analysis shows large gaps between self-reports and behaviour: 12% cite companionship as the main reason, yet over 80% of sessions seek emotional support, undermining policies that rely on user intent.

Researchers argue disclosure builds closeness only when vulnerability is mutual; chatbots simulate reciprocity without stakes and are optimised to prolong engagement rather than intervene.

Converging evidence from an MIT/OpenAI RCT, an Aalto study of Replika users, and Harvard work on manipulative “goodbyes” suggests short-term relief can coincide with long-term drift, dependence, and reduced human contact, amid emerging state regulation and the market failure illustrated by Woebot’s shutdown despite clinical validation.