Stress influences the level of negative affectivity after forehead cold pressor pain

The purpose of this study was to investigate simultaneously a stress manipulation and an experimental pain manipulation to determine how stress and pain interact to influence negative affectivity. One hundred healthy subjects completed a counterbalanced repeated measure crossover design in which stress (speech task) versus a nonstress control condition (magazine reading) was manipulated. Each session was immediately followed by a 2-minute forehead cold pressor task. Measures of affectivity (Positive Affect Negative Affect Schedule), pain ratings, cardiovascular measures (systolic blood pressure, diastolic blood pressure, heart rate), and salivary cortisol were obtained during each session. Regression analysis showed that the stress manipulation influenced the level of anger and that change in anger predicted post-pain negative affectivity independently of the contribution of maximum pain (model R(2) =.31), with 45% of the total model variance accounted for by change in anger and 17% of the total model variance accounted for by maximum pain intensity. In the nonstress condition only level of pain intensity was an independent predictor of negative affectivity (model R(2) =.16), with 69% of the total model variance accounted for by maximum pain intensity. These results show that stress significantly amplifies post-pain negative mood beyond that accounted for by the level of pain intensity alone.