What people do may be a better marker of depression than how people say they are feeling. Behavior can be objectively measured using mobile phones. It is an active sensing and prediction platform to identify behavior changes when individuals suffer from common colds, influenza, fever, stress and depression.

Studies have found a strong relationship between location (using GPS) and clinical PHQ-9 scores. The daily pattern, variability and extent of communications can also be analysed to give valuable clues to changing trends in activity. It is possible to monitor depression passively using phone sensor data. This has significant public health implications. Most people are unwilling to answer questions repeatedly over long periods of time, while passive monitoring could improve the management of depression in populations, allowing at risk patients to be treated more quickly as symptoms emerge or monitoring patients’ responses during treatment.

The efficacy of smartphone sensors and self reporting for mental health care has not been proven yet and remains a very important research question in the pervasive health community.

2 billion people already carry their smartphone with them most of the time. Even the cheaper models have sensors that can track movement and activity, generating data to provide insights into our wellbeing.

StayClose is a free family care app, powered by Touchkin’s predictive care platform. The app helps families care for loved ones while being afar by enabling them to know how they are, without having to ask. They can also share a touch or video moment, or do something to help, like send a ride to take them to the doctor.

For example, when a person is depressed, their phone is likely to show more time spent at home, unusually low activity, changes in communication or sleep patterns. It is possible for a machine learning engine to learn anyone’s phone’s normal sensor patterns and generate alerts if unusual activity indicates any health issues.

I look forward to collaborating with Touchkin for a few pilot studies in London.