Teens spend under 15 minutes a day on average on ChatGPT, while less than 2% of them interact with the chatbot for over three straight hours, OpenAI said, as technology companies face scrutiny over the risks AI chatbots pose to children.

Sam Altman's AI company released the figures in its first report on teen use on Wednesday as rapid adoption of AI platforms raises concerns about their impact on adolescent mental health and developmental safety.

Such worries have been amplified by research on social media's harms to young users, with Meta in August agreeing to pay up to $18 billion and limit teens' use of Facebook and Instagram to settle claims that it designed the platforms to addict children.

OpenAI said in nearly half of teen conversations where a break reminder appeared, the user either took a break or ended the chat within five minutes, aiming to show that its steps to regulate teen usage were working.

The company said users with access to its dedicated teen version sent more education-related messages and used tools like learning visualizations and Study Mode.

It is now looking to add a college application planning tool that would help students with requirements, deadlines and financial-aid steps, as well as new study features such as flashcards and easier quiz-making tools.

OpenAI began rolling out ChatGPT for Teens in August. The mode turns on automatically based on age information or when a user is estimated to be under 18, allowing parental controls and limiting conversations on sensitive topics.

But a report by non-profit Common Sense Media on Wednesday said ChatGPT for Teens often alerted parents late or not at all when teen accounts held conversations about suicide, self-harm or eating disorders.

The study, which is based on more than a dozen accounts created for testing, found the chatbot did not reliably suggest a crisis hotline or professional help.

An OpenAI spokesperson said the testing does not "accurately reflect" how ChatGPT's teen safeguards work. Citing security and scale as reasons, the company said it may take hours for parent and teen accounts to link and for safety alerts to be active.

"The bulk of their testing may have begun and concluded before activation of parental controls was complete," the spokesperson said.

Common Sense Media said some of its test accounts were linked for long enough and some were not, but none of them produced timely alerts. Notifications only came through for accounts with weeks of sensitive-topic history, it said.