The current institution-based model for mental healthcare delivery faces challenges posed by an increase in diagnoses of mental illness, shortage of mental healthcare professionals, and increasing cost of treatment. In this article, we survey the current state of one potential alternative, the mobile health (mHealth) in mental health research. Three approaches are outlined based on the researched literature: the first approach focuses on mobile applications that rely on smartphone’s built-in sensors to capture relevant data; the second approach looks at the use of wearable devices that record the patients’ data; and finally the hybrid systems that make use of both approaches. This paper aims to summarise the methodology of 39 studies and their outcomes. This review will allow researchers and healthcare providers to gain a valuable insight into existing approaches and contemplate needed future improvements that would lead to the successful utilisation of technology in mental healthcare delivery. © 2022 Elsevier B.V., All rights reserved.