An international team of researchers has shown that measurements taken from a person’s fingertip could help identify physical patterns associated with stress, anxiety and depression. These measurements were then combined with machine learning to investigate whether people reporting symptoms of stress, anxiety or depression displayed recognisable physical patterns, given that stress and anxiety can affect the nervous system, heart rate, circulation and metabolism. Participants completed a widely used 21-question assessment covering depression, anxiety and stress before undergoing repeated fingertip measurements. It also measured substances associated with how cells produce and use energy, as well as skin temperature and heart rate. Machine-learning models were then used to compare the physical measurements with participants’ questionnaire results.