Perceived stress may mediate the impact of negative life events on common cold susceptibility: A causal mediation...

Experiencing negative events can harm health, partly by impairing immunity. However, not everyone exposed to adversity experiences illness, raising questions about the mechanisms through which events translate into poorer health. This study investigates whether perceived stress mediates the effects of negative life events on immune-related outcomes, specifically susceptibility to the common cold. Using secondary data from the Pittsburgh Cold Study 3, we analyzed 213 healthy adults inoculated with a cold virus who reported recent life events and perceived stress prior to inoculation; cold symptoms were assessed during quarantine. Causal mediation analyses suggested that perceived stress may mediate the relationship between high cumulative negative life events (7+ events) and increased cold symptom severity and subjective infection criteria. Exploratory analyses of specific events (assault, bereavement) and sex differences yielded preliminary findings, with bereavement showing a protective effect. These findings highlight the role of stress appraisal and suggest targeting perceived stress in health interventions.