The growing understanding that mood disorders are dynamic in nature and fluctuate over variable epochs of time has compelled researchers to develop innovative methods of monitoring mood. Technological advancement now allows for the detection of minute-to-minute changes while also capturing a longitudinal perspective of an individual's illness. Traditionally, assessments of mood have been conducted by means of clinical interviews and paper surveys. However, these methods are often inaccurate due to recall bias and compliance issues, and are limited in their capacity to collect and process data over long periods of time. The increased capability, availability and affordability of digital technologies in recent decades has offered a novel, non-invasive alternative to monitoring mood and emotion in daily life. This paper reviews the emerging literature addressing the use of digital mood tracking technologies, primarily focusing on the strengths and inherent limitations of using these new methods including electronic self-report, behavioural data collection and wearable physiological biosensors. This developing field holds great promise in generating novel insights into the mechanistic processes of mood disorders and improving personalised clinical care. However, further research is needed to validate many of these novel approaches to ensure that these devices are indeed achieving their purpose of capturing changes in mood.
IntroduCtIonOver the last two decades the technological advances in personal devices have been unprecedented. Due to the ability for immediate communication and access to information, we now live in an era in which for the first time 'bodily functions' can be tracked in real time by individuals themselves. This data can then be simultaneously communicated in real time to systems for storage and analysis, allowing for the development of databases sufficiently large and detailed to meaningfully make sense of biometric data. Yet, in practice, few of these technologies are used, especially by clinicians, either for research or day-to-day clinical care. In psychiatric practice, these technologies have the potential to track the symptoms of mood disorders as devices can log objective measures of mood, arousal, activity and sleep, and allow users to input subjective experiences. Additionally, devices have the potential to be part of daily personal care, providing alerts for pharmacological and psychological treatment adherence and undertaking physical activity. Promisingly, with further research, there is the potential for these devices to be embedded within routine clinical management, as algorithms for predicting the dynamic nature of mood disorder presentations and treatment responses are developed. In order to progress to this stage, it is necessary to examine the nature of mood disorders and how existing technologies are being employed to measure this. This review examines the digital techniques that have been used by researchers to capture the dynamic nature of mood disorders and points to ...