Digital mood-monitoring technology, such as mood-monitoring applications, is increasingly advocated within clinical research and is a potentially effective method to engage and empower youth. However, limited evidence is available on this type of technology.

(1) To assess the evidence for the use of mobile mood-monitoring applications in youth; (2) to explore what available smartphone application would be most suitable to monitor mood from the perspective of young people; (3) to examine whether mood-monitoring applications are useful for investigating mood instability in youth; (4) to explore the utility and acceptability of using the mood-monitoring application from young people's and clinicians’ perspectives.

To investigate how mood-monitoring applications can be used to support the assessment, engagement and empowerment of young people presenting to mental health services with a range of diagnoses in which mood instability forms a key component.

A systematic review using a Cochrane methodology was conducted. After obtaining ethical approval, this study will also employ a mixed methods approach, through which quantitative findings (e.g., digital mood-monitoring data) will be furnished with an in-depth understanding of young people's views on digital mood-monitoring technology.

Findings from a systematic review focusing on the evidence for the psychometric properties, usability and clinical impacts of applications in youth will be presented. Preliminary results from consultations groups and plans for future research will also be discussed.

Evidence acquired through this research can potentially influence mental health policies and result in more innovative (adjunct) interventions and improved outcomes for young people with mood instability.

The authors have not supplied their declaration of competing interest.