Experimentally Induced Post-Event Rumination Alters Biological Stress Response Patterns to Repeated Stress

Rumination-the repetitive negative thinking about stressful events-impairs biological stress system activity. However, its impact on the habituation of stress responses, particularly of the sympathetic nervous system (SNS) and hypothalamus-pituitary-adrenal (HPA) axis, remains understudied. This study examined how post-event rumination affects the habituation of biological responses to repeated stress.

In this randomized experimental study, 47 participants were assigned to a rumination or control condition and exposed to two consecutive stress tasks. After the first stress exposure, the rumination group engaged in guided post-event rumination, while the control group reflected on a neutral everyday topic. Biological markers of HPA axis (cortisol) and SNS activity (salivary alpha-amylase, sAA), as well as psychological variables (positive and negative affect, state rumination), were assessed before and after each stressor.

Compared with the control group, participants in the rumination condition showed reduced habituation of HPA axis activity ( t(45) =-2.01, p =.025) and increased SNS activation over time, as indicated by rising sAA levels ( t(45) =-2.03, p =.024). No significant group differences were observed in self-reported affect or state rumination.

Post-event rumination impairs biological habituation to repeated stress. These findings suggest that rumination disrupts physiological stress adaptation, which may contribute to prolonged stress responses and increased risk for stress-related health problems. Interventions targeting rumination may support more adaptive stress regulation and promote better health outcomes.