The situation of mental disorders is always more worrying while the IoT has proven to be an ally of medicine for its ability in receiving, processing, and analyzing great quantities of data.OnMind is a biofeedback device for psychophysiological disorders, especially for depression and anxiety. OnMind has a wrist-band, that monitors stress (HRV, HR, SpO2, EDA) and environmental parameters (Light and Temperature), an App for the patient and a Platform for the therapist. App shows graphics and behavior-related tips to improve user well-being. On the platform patients data are shown. The patient understands the body’s reaction to stress and how the environment influences his mood. It basis on the literature related to the circadian rhythms, with a focus on HRV, EDA, sleep phases and light.