JMIR Publications

ABSTRACT

Background:

Most smartphones and wearables are nowadays equipped with location sensing (using Global Positioning System and mobile network information) that enable continuous location tracking of their users. Several studies have reported that the amount of time an individual experiencing symptoms of Major Depressive Disorder (MDD) spends at home a day (i.e., home stay), as well as various mobility related metrics, are associated with symptom severity in MDD. Due to the use of small and homogeneous cohorts of participants, it is uncertain whether the findings reported in those studies generalize to a broader population of individuals with the MDD symptoms.

Objective:

The objective of this study was to examine the relationship between overall severity of the depressive symptoms, as assessed by the eight-item Patient Health Questionnaire (PHQ-8), and median daily home stay over the two weeks preceding the completion of a questionnaire in individuals with MDD.

Methods:

We used questionnaire and geolocation data of 164 participants with MDD collected in the observational Remote Assessment of Disease and Relapse – Major Depressive Disorder (RADAR-MDD) study. The participants were recruited from three study sites: King’s College London (KCL) in the UK, Vrije Universiteit Medisch Centrum (VUMC) in Amsterdam, the Netherlands, and Centro de Investigación Biomédica en Red (CIBER) in Barcelona, Spain. We utilised a linear regression model to investigate the relationship between home stay and overall severity of the MDD symptoms. Participant age at enrolment, gender, occupational status, and data quality were included in the model as additional explanatory variables. 95% two-sided confidence intervals (CI) were used to evaluate the significance of the model variables.

Results:

Participant age and severity of the MDD symptoms and were found to be significantly related to home stay (CI: 0.161; 0.325 and 0.015; 0.184 respectively), with older and more severely affected individuals spending more time at home. The association between home stay and symptom severity appeared to be stronger on weekdays than on weekends (CI: 0.023; 0.178 and -0.079; 0.149 respectively). Furthermore, we found a significant modulation of home stay by occupational status, with employment reducing home stay.

Conclusions:

Our findings suggest that home stay is associated with symptom severity in MDD and demonstrate the importance of accounting for confounding factors in future studies. In addition, they illustrate that passive sensing of individuals with depression is feasible and could provide clinically useful information to monitor the course of illness in patients with MDD.