Ambulatory assessment smartphone app 'promising addition' to depression screening tools

Mood indicators assessed in an ambulatory setting appeared to be a promising addition to multimodal depression screening tools, according to study results published in PLOS One.

“[Ambulatory assessment] is a feasible approach to repeatedly assess mood ratings over a longer period, which is the basis for the calculation of mood indices,” Sebastian Burchert, Dipl.-Psych, of the department of education and psychology at the Free University of Berlin, and colleagues wrote. “Progress in this field of research has the potential to translate into improved mental health screening algorithms that go beyond the standard assessments. In this context, it has also been pointed out that combinations of multiple measurements on the basis of mobile technology may improve diagnostic accuracy and the prediction of treatment trajectories in the mental health field, an approach that is already far more common in medical diagnostics.”

The investigators sought to conduct a preliminary evaluation of the depression screening component of Moodpath, a mental health app that uses ambulatory assessment to evaluate depression symptoms according to ICD-10 criteria, as well as mood in daily life. They randomly selected 113 Moodpath users via consecutive sampling and had them fill out the Patient Health Questionnaire (PHQ-9) following completion of 14 days of ambulatory assessment with daily question blocks in the morning, midday and evening. Further, they assessed the psychometric properties, including sensitivity, specificity and accuracy, of the ambulatory Moodpath screening based on the retrospective screening result of the PHQ-9. They used regression models to calculate and investigate multiple indicators of mood dynamics, such as average, inertia and instability, for their individual and incremental predictive value.

Results showed the PHQ-9 score and the ambulatory assessment Moodpath depression score had a strong linear relationship. Screening via the app demonstrated a high sensitivity of .879 and an acceptable specificity of .745. Depending on the number of days with mood data that were analyzed, different indicators of mood dynamics covered significant amounts of PHQ-9 variance.

“[Ambulatory assessment] and PHQ-9 shared a large proportion of variance but may not measure exactly the same construct,” Burchert and colleagues wrote. “This may be due to the differences in the underlying diagnostic systems or due to differences in momentary and retrospective assessments. Further validation through structured clinical interviews is indicated.”