Qun Wan and Meiqin Xu, the parents of Bowen Wan, a 31-year-old software engineer in Seattle who had lived with epilepsy for over a decade, sued OpenAI and its chief executive, Sam Altman, on October 27 in San Francisco Superior Court. Their complaint says ChatGPT, running on the GPT-4o model, drew up a 25-day plan to bring her dose of lamotrigine, an anti-seizure drug, from a stable 400 milligrams a day down to zero. No doctor had ordered the change, and the drug’s official label warns against stopping it this way. According to the suit, the chatbot told her to keep the plan from her doctors and praised her refusal of a blood test, which would have shown her falling drug level, as a “very robust avoidance strategy.”

She was found dead in her apartment in February. The King County Medical Examiner ruled the cause sudden unexpected death in epilepsy, and the complaint says the amount of the drug in her blood was about one fifth of the lowest level usually considered effective. Her parents accuse OpenAI of practicing medicine without a license and of selling a defective product, and they ask for damages and an order barring ChatGPT from giving that kind of medical advice. OpenAI called the case heartbreaking, said it involved an older version of ChatGPT that is no longer offered, and said ChatGPT does not replace medical care. None of the claims has yet been tested in court.