Smartphone Photoplethysmography Pulse Rate Covaries With Stress and Anxiety During a Digital Acute Social Stressor

Abstract

Objective Heart rate is a transdiagnostic correlate of affective states and the stress diathesis model of health. While most psychophysiological research has been conducted in laboratory environments, recent technological advances have provided the opportunity to index pulse rate dynamics in real world environments with commercially available mobile health (mHealth) and wearable photoplethysmography (PPG) sensors that allow for improved ecologically validity of psychophysiological research. Unfortunately, adoption of wearable devices are unevenly distributed across important demographic characteristics, including socioeconomic status, education, and age making it difficult to collect pulse rate dynamics in diverse populations. Therefore, there is a need to democratize mHealth PPG research by harnessing more widely adopted smartphone-based PPG to both promote inclusivity and examine whether smartphone-based PPG can predict concurrent affective states. Methods In the current preregistered study with open data and code, we examined the covariation of smartphone-based PPG and self-reported stress and anxiety during an online variant of the Trier Social Stress Test (TSST), as well as prospective relationships between PPG and future perceptions of stress and anxiety in a sample of 102 university students. Results Smartphone-based PPG significantly covaries with self-reported stress and anxiety during acute digital social stressors. PPG pulse rate was significantly associated with concurrent self-reported stress and anxiety (b = 0.44, p = 0.018) as well as prospective stress and anxiety at the subsequent time points, although the strength of this association diminished the farther away pulse rate got from self-reported stress and anxiety (lag 1 Model: b = 0.42, p = .024; lag 2 model: b = 0.38, p = 0.044). Conclusions These findings indicate that PPG provides a proximal measure of the physiological correlates of stress and anxiety. Smartphone-based PPG can be used as an inclusive method for diverse populations to index pulse rate in remote digital study designs.

Technological Innovations in Biobehavioral and Psychosomatic Medicine

“…A comprehensive overview of technological innovations is provided with the goal that these and related innovations will be incorporated into research and clinical practice. The articles in this issue address the following general topics: the use of biological and behavioral sensors that are linked to user smartphones (8)(9)(10)(11)(12)(13), the use of technology in clinical settings and issues related to VHs in clinical settings (14,15), digital mental health interventions (16,17), and the importance of reducing health disparities in technological development and implementation of technological innovation (18).…”