They are working with UCLA and pharmaceutical company Biogen to see if data like facial expressions, typing metrics, and sleep patterns could signal mental-health concerns, so Apple could then warn people if they are at risk. If successful, Apple could improve the detection of conditions, for tens of millions of people, but the extent of user tracking could have privacy concerns. To address them, Apple aims for algorithms that work on users' devices and don't send the data to Apple servers. Link
