AI-powered apps offering medical diagnoses at the click of a button are often limited by biased data and a lack of regulation, leading to inaccurate and unsafe health advice, a new study found.

McGill University researchers presented symptom data from known medical cases to two popular, representative apps to see how well they diagnosed the conditions. While the apps sometimes gave correct diagnoses, they often failed to detect serious conditions, according to findings published in the Journal of Medical Internet Research. This potentially resulted in delayed treatment.

A new study from the University of Georgia suggests people posting in Reddit’s r/selfharm community are likely seeking support for negative emotions.