(PS9-67) Physiological Markers of Perseverative Cognition in Individuals with Active and Remitted Depression

Background: Perseverative cognition (PC) is a core feature of internalizing psychopathology and has been associated with physiological dysregulation in the autonomic nervous system, including alterations in heart rate and heart rate complexity. While prior research has linked PC to these physiological markers, less is known about the within-person, moment-to-moment relationships between PC and physiological functioning in daily life. Identifying physiological antecedents of heightened PC is critical for informing real-time detection of moments when PC is likely to occur, and for developing interventions that can be delivered in moments of risk. This study examined how physiological markers predict PC across three groups: individuals who have never experienced depression (HC), individuals with remitted major depressive disorder (rMDD), and a small preliminary sample of individuals with active major depressive disorder (aMDD) and active suicidal ideation.

Methods:  Young adults (N=123; n=48 HC, n=51 rMDD, n=24 aMDD) completed ecological momentary assessment (EMA) up to six times daily for 7–9 days while wearing a Hexoskin smart shirt to continuously collect electrocardiogram (ECG) during waking hours. Degree of PC engagement was defined by Likert scale ratings (from not at all - very much) of ruminative brooding and worry. We examined physiological markers of autonomic functioning, including heart rate (HR) and signal complexity indexed by ɑ1 from detrended fluctuation analysis, measured approximately 30 minutes before the PC ratings. Multilevel models assessed how fluctuations in physiological markers (e.g., HR, ɑ1) predicted PC in daily life, after controlling for activity levels.

Results: Individuals with active MDD reported the highest levels of PC, followed by remitted MDD and HCs. The aMDD group had the highest average HR, while the rMDD group exhibited the highest levels of self-similarity (ɑ1), followed by aMDD and HC groups. Multilevel models assessing fluctuations in HR and ɑ1 as proximal predictors of momentary PC revealed that momentary increases in HR and ɑ1 significantly predicted PC (β = 0.017 - 1.182, p < 0.03). Individuals in the rMDD and aMDD groups showed significantly higher levels of PC than HC. Additionally, the relationship between HR and PC significantly differed for the rMDD group, with a weaker association compared to the other two groups. 

Discussion: Identifying physiological markers that precede fluctuations in PC may provide a foundation for the development of real-time passive monitoring and intervention strategies, such as wearable technology and biofeedback, to mitigate PC in daily life. Notably, measuring physiological indices before PC assessments highlights the potential for just-in-time interventions by enabling the prediction of moments of heightened risk. Moreover, this study enhances our understanding of the physiological antecedents of PC, a transdiagnostic feature of numerous mental health conditions.