The aim of IMMERSE (Implementing Mobile Mental health Recording Strategy for Europe) is to advance person-centered mental health care by including individuals seeking help for mental health problems in their treatment process and decision-making. For this purpose, IMMERSE will develop a clinical digital health tool, Digital Mobile Mental Health (DMMH), fed by data from ecological momentary assessment (EMA), mobile sensing and machine learning. In close collaboration with stakeholders, the implementation of the DMMH will be evaluated at 8 sites in 4 European countries (Belgium, Germany, Scotland, and Slovakia) in a cluster Randomized Controlled Trial (cRCT)