“I’m Ready This Time”: Investigating physiological and emotional habituation to repetitive social stress

Repetitive stress is at the nexus of acute and chronic stress, and there is limited knowledge about how physiological and emotional responses change with repeated exposure. We examined stress-related biomarkers and emotional responses to repeated social stressors, and we tested behavioral moderators. In Study 1, 42 adults completed the Trier Social Stress Test (TSST) twice, 4 months apart. Serum inflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α]), blood pressure, pulse, salivary cortisol, and state-level anxiety were measured surrounding the stressor. In Study 2, 84 married individuals completed two 20-minute discussions of contentious topics in the marriage, 1 month apart. Serum IL-6, TNF-α, blood pressure, pulse, salivary cortisol, and state affect were collected surrounding the conflict. Trained experimenters rated positive and negative behavior during the conflict. In the repetitive Trier paradigm, participants reported less anxiety (Ps = .048) and had higher anticipatory IL-6 responses (P = .014) at Visit 2, compared to Visit 1. In the repetitive marital conflict paradigm, participants had lower positive affect (P = .0004), as well as systolic blood pressure (SBP) (P = .009), diastolic blood pressure (P = .0003), and pulse (P = .027) habituation at the second visit. Objectively rated negative conflict behavior interacted with visit to predict TNF-α (P = .025) and SBP (P = .037) responses. Positive conflict behavior did not moderate outcomes (Ps > .06). Stress-sensitive systems can habituate or sensitize to even nontraumatic, repetitive social stressors. Patterns of habituation or sensitization may vary by time between repetition, type of social stressor, stress-sensitive system, and participant behavior.