Paradoxical effects of social support on blood pressure reactivity among defensive individuals

Abstract

Background: Social support can reduce cardiovascular responses to an acute stressor. However, prior clinical research suggests that defensive individuals may react negatively to social support. Purpose: This experiment examined whether emotional support provided during a speech stressor would escalate rather than decrease blood pressure (BP) reactivity among defensive individuals. Methods: After completing personality measures, 176 female undergraduates were randomly assigned to give a speech in 1 of 3 social conditions: alone, or with a neutral or supportive confederate present. Mean arterial BP was assessed at baseline, immediately before, and during and after the stressor. Results: In the supportive condition, defensiveness predicted higher BP reactivity during anticipation (β = .35, p = .04) and delivery of the speech (β = .32, p = .03), and longer recovery to baseline BP levels (β = .35, p = .01). In the absence of support (i.e., alone and neutral conditions), defensiveness was not associated with BP reactivity. Defensiveness also predicted greater dissociation between subjective stress and BP responses (β = .35, p = .05), but only in the supportive condition. Conclusions: According to results, the provision of social support during stressors does not benefit defensive individuals' BP reactivity but has the opposite effect. © 2006 by The Society of Behavioral Medicine.