Trajectories of Depression: Investigating the Correlation between Human Mobility Patterns and Mental Health Problems by means of Smartphones

Depression does not only affect the personal life of individuals and their families and social circles but it has also a strongly negative economic impact as shown in several reports. According to a recent study, workers in the United Kingdom suffer high levels of depression than those anywhere else in Europe. The survey found that 1 in 10 employees had taken time off at some point in their working lives because of depression problems. Novel strategies for tackling the problem of depression and preventing suicides are needed. We believe that new emerging technologies, in particular mobile ones, together with the possibility of mining large amount of data in real-time can help to tackle this problem in new and more effective ways.

Existing interview-based studies have shown that depression is significantly associated with a marked decline of physical activity. The goal of this project is to investigate how mobile phones can be used to collect and analyse mobility patterns of individuals in order to understand how mental health problems affect their daily routines and behaviour and how potential changes can be automatically detected. In particular, mobility patterns and levels of activity can be quantitatively measured by means of mobile phones, exploiting the GPS receiver and the accelerometers embedded in the devices. The data can be extremely helpful to understand the behaviour of a depressed person, and in particular, to detect potential changes in his or her behaviour, which might be linked to a worsening depressive state. By monitoring this information in real-time, health officers and charity workers might intervene by means of digital behaviour intervention delivered through mobile phones or by means of traditional methods such as by inviting the person for a meeting or by calling him or her by phone.

In order to support these novel applications, it is necessary to build mathematical tools for analysing the mobility traces in real-time for the detection of gradual or sudden changes related to the emotional states of the individual. More specifically, we plan to devise analytical techniques for studying the relationships between human mobility patterns and emotional states. We plan to use existing datasets of human mobility and to collect data by means of a smartphone application distributed to people affected by depression. This can be considered as a sort of pilot study for a wider deployment of these technologies and it will provide a sound theoretical basis for further studies in this area. Finally, a key aspect of the proposed research work is the implementation of mechanisms for preserving the privacy of the individuals involved in the study.

We believe that the proposed research programme can have a significant societal impact. Indeed, depression is a major issue in the United Kingdom and has profound psychological, social, and economic implications for individuals, families and communities. The long-term impact will be in novel methods of intervention and support, based on the outputs of the proposed work. Indeed the analytical techniques investigated in "Trajectories of Depression" can be used as a basis for novel systems for providing real-time support to individuals when they really need it without a direct interaction with health officers. By doing so, individuals that are not collaborative because of their condition can also receive prompt help and attention in order to prevent a worsening of their condition and, in some cases, suicide attempts. Moreover, the techniques can also be used to concentrate resources on individuals that really need help at a certain point in time. To summarise, the project can really lead to the improvement of the well-being of thousands of individuals and it will improve the effectiveness and efficiency of delivery of Social Welfare services.

It is worth noting that Dr. Paul Patterson, Public Health Research Programme Manager at Youthspace, Birmingham and Solihull Mental Health NHS Foundation Trust is a member of the Advisory Committee and will help to steer the project in directions that will provide a direct benefit to the communities in the coming years. Dr. Patterson and the colleagues at the Stirling Suicidal Behaviour Research Laboratory will also help in establishing links to charities that are active in this area (such as Mind and The Samaritans).

Given the highly interdisciplinary nature of this work, the proposed research programme will benefit various communities in Computer Science, Health Sciences and Psychology. As far as Computer Science is concerned, we believe that the project will lead to novel insights and contributions in different areas including Ubiquitous Computing, Data Mining, Systems, and, potentially Security as discussed in the "Academic Beneficiaries" section. With respect to Health Sciences and Psychology, for the first time, researchers will have the possibility of accessing quantitative data to validate theories and models that have been evaluated only by means of qualitative information, such as interviews. This can really lead to a step change in studying depression, especially in terms of its evolution over time and its impact on the daily life of individuals. It will provide new ways for providing direct help to them, for example through Digital Behaviour Change Interventions through mobile phones.

We are also planning an outreach programme for disseminating the finding of the project among young people. Activities in schools might also be an occasion for discussing issues related to depression and suicides in collaborations with charities working on these themes. The project will benefit from the fact that the School of Computer Science at the University of Birmingham is heavily involved in the Computing at Schools initiative. We also plan an exhibit at the Thinkthank Science Museum in Birmingham. We plan to engage with students in our Undergraduate and Master programmes by offering for example guest lectures on topics related to the project, discussing the use of mobile technology and large-scale data mining.

Finally, we believe that the outputs of this project can potentially be translated into commercial products in the future. We plan to work closely with NEC, our industrial project partner, in order to explore uses of the findings of "Trajectories of Depression". The company has also expressed a strong interest in the computational aspects of the project, since it provides an interesting application scenario for investigating issues related to large-scale real-time processing and mining of personal data, in particular in the healthcare sector.