Background. We propose the investigation of interpersonal physiological synchrony (IPS), which refers to degree of synchrony between continuous measures of autonomic nervous system activity of people, as a predictor of suicidal thoughts and behaviors (STBs). Synthesizing IPS empirical findings and theoretical frameworks implies IPS between clinicians and suicidal patients may reflect interpersonal dynamics of emotion contagion and interpersonal emotion regulation, which, in turn, could predict STBs: clinician employment of interpersonal emotion regulation strategies by engaging with the "stimulus" (i.e., the suicidal patient) that triggers overwhelming, distressing emotions via emotion contagion (i.e., the suicidal patient's pre-suicidal emotional state) could result in positive, congruent IPS patterns, while intrapersonal emotion regulation strategies that involve disengaging from or avoiding the suicidal patient could manifest in the form of negative, incongruent synchrony. Thus, we propose a prospective study that examines the association between IPS and STBs in patient-clinician dyads and its application in an outpatient setting as a physiological predictor of STBs. The study will feature repeated heart rate variability (HRV) and STB measurement up to six times over eight weeks and the following aims: (1) to test the acceptability and feasibility of IPS implementation in a psychology outpatient setting; (2) to establish the construct validity of IPS by examining the significance of hypothesized coregulatory effects in clinician-patient dyads as measured by HRV and their association with patient STB severity; (3) to evaluate whether IPS significantly predicts STBs above and beyond traditional interpersonal measures; and (4) to explore the moderation effect of various patient, clinician, and dyadic characteristics on coregulation effects and IPS association with STBs. To this end, we will test the following hypotheses: (1) clinician and patient HRV will have a significant effect on each other over time, even after accounting for their baseline HRV; (2) IPS will significantly covary with patient STBs over time even after the inclusion of self-report interpersonal measures variance; (3) both patient and clinicians will report high acceptability and feasibility of repeated physiological monitoring. Aim 4 will be pursued as an exploratory approach without any a priori hypotheses.
Methods. Participants will be doctoral-level student clinicians and their outpatients from a university psychology clinic. The main study battery will involve IPS measurement in the form of HRV data collected through an electrocardiogram as clinician-patient dyads complete a suicide risk assessment and crisis response planning and the patient administration of the Columbia Suicide-Severity Ratings Scale. Data on potential moderators (e.g., sociodemographics) and confounding variables (e.g., psychotropic drug use) will also be collected. The main battery will be readministered weekly up to six times over the course of eight weeks. Data on acceptability and feasibility of physiological monitoring will also be collected.
Impact and Future Directions. To our knowledge, this will be the first study to utilize IPS in prediction of STBs. Potential impact includes the development of a novel predictor of suicide risk, adoption of physiological monitoring to improve suicide prediction in healthcare settings, better understanding of interpersonal context influence on STBs, and destigmatization of clinician response to suicidal patients.
