How tech companies scour our digital lives for clues to our health

Mindstrong Health, a mental health start-up, has developed a research platform to monitor users' phone habits, looking at changes in taps and clicks for hints about mood and memory changes associated

Your digital footprint — how often you post on social media, how quickly you scroll through your contacts, how frequently you check your phone late at night — could hold clues to your physical and mental health.

That at least is the theory behind an emerging field, digital phenotyping, that is trying to assess people’s well-being based on their interactions with digital devices. Researchers and technology companies are tracking users’ social media posts, calls, scrolls and clicks in search of behavior changes that could correlate with disease symptoms. Some of these services are opt-in. At least one is not. People