Consider this situation: A family member starts avoiding social gatherings, doesn’t respond to messages quickly, becomes isolated for long periods of time, and stays online late at night becoming sleep deprived.

You sense anxiety and depression in social media posts and you automatically wonder if your family member is undergoing some problems. That is the basis of digital phenotyping, a term coined by the Harvard T.H. Chan School of Public Health for the emerging field, which is focused on trying to assess people’s well-being based on their interactions with digital devices, such as smartphones.

The data generated from extensive smartphone use can shed light on our physical and emotional health. Smartphones generate two forms of digital data: Active or user-generated data including content in texts, calls, and social media (for social engagement); and passive data including spatial location, time spent in various locations, driving speed, and phone usage patterns all collected via the phone’s sensors.

Facebook recently announced an algorithm that scans posts to see if users are exhibiting signs of suicidal thoughts and alerts a Facebook review team.

Mindstrong Health, a California-based startup, has developed a research app to continuously monitor users’ phone habits, keyboard accuracy, and speed for hints about mood and memory changes associated with depression. Paul Dagum, CEO of Mindstrong Health, believes that this data can be used at an aggregate level for public health, such as creating a heat map of the planet to show spots of emotional volatility or cognitive decline from stress, contagion, or toxins.