Mental health counselor Nicole Doyle was stunned when the head of the U.S. National Eating Disorders Association showed up at a staff meeting to announce the group would be replacing its helpline with a chatbot.

A few days after the helpline was taken down, the bot — named Tessa — would also be discontinued for providing harmful advice to people in the throes of mental illness.

"People ... found it was giving out weight loss advice to people who told it they were struggling with an eating disorder," said Doyle, 33, one of five workers who were let go in March, about a year after the chatbot was launched.