Heart rate increases during social isolation: Matter of depressive mood and self-reported infection symptoms

While the mental health challenges posed by quarantine are well-documented, its physiological effects remain less understood. We examined cardiovascular trajectories over a 6-day quarantine following common cold infection, utilizing data from the Pittsburgh Cold Study 3 (n = 213, 2007-2011). Specifically, we explored the relationship between depressive mood and heart rate (HR) patterns, hypothesizing that individuals prone to depressive mood might experience altered arousal during quarantine. We conducted similar analyses for blood pressure (BP) as well. Our findings revealed that, on average, HR increased during quarantine. Notably, individuals reporting higher depressive mood levels exhibited lower initial HR but experienced a sharper increase throughout the quarantine period. In contrast, no significant linear or quadratic changes were observed in systolic blood pressure (SBP). However, initial analyses did identify significant linear changes in diastolic blood pressure (DBP) and mean arterial pressure (MAP). These changes in DBP and MAP were not influenced by depressive mood and lost significance in sensitivity analyses that accounted for infection-related factors, health behaviors, and socio-demographic variables. Interestingly, HR trajectories remained significant in sensitivity analyses but lost significance when self-reported symptoms were included. Self-reported symptoms partially mediated the relationship between depressive mood and HR increases, suggesting that individuals with higher depressive tendencies also reported more infection-related symptoms, contributing to increased HR. These findings highlight how midterm social isolation can elevate HR, particularly in individuals prone to depressive mood. However, the absence of a control group limits broader interpretations, emphasizing the need for further research.