Recent advances in smartphone technology have revealed new opportunities for the diagnosis, monitoring and provision of mental health care. Such digital approaches have the potential to enhance our understanding of the course of mental disorder, enable early diagnosis and generate new treatment targets. However, issues relating to mobile phone ownership, misuse of clinical data, commercial devices and the ethics of such approaches need to be overcome if smartphones are to be routinely used in mental health care. This article reviews the potential as well as the challenges posed by the use of such technologies in mental health settings. To read the full article, log in using your MPFT NHS OpenAthens details.