An artificial intelligence (AI) programme trained to scour Facebook posts for "linguistic red flags" which could be a sign of depression identified the condition up to three months earlier than health services, a US study has found. In early tests the machine learning algorithm performed as well as existing screening questionnaires which are used to identify depression – but it has the advantage of being able to run "unobtrusively" in the background, the authors note. Recently a backlash against platforms like Facebook, from ministers and parents concerned about the damaging impact on children wellbeing, has led to calls for stricter age and usage limits. But US researchers behind the new tool tool say the wealth of information in social media pages could one day be used to help unobtrusively screen for mental health conditions. 'This is why I deleted Facebook, and I really don't miss it' 'This is why I deleted Facebook, and I really don't miss it' These early warning signs include mentions of loneliness or isolation, such as "alone", "ugh" or "tears" as well as the timing and length of posts.