Verbal support from a stranger reduces the development of mechanical hypersensitivity: behavioural, electrophysiological evidence and the moderating role of attachment styles

Abstract

Various forms of social support have been evidenced to diminish acute pain ratings and modulate physiological responses to acute pain stimuli, with adult attachment styles moderating this effect. However, only one study to date has examined the impact of the social context (using a hand-holding intervention by a romantic partner) on experimentally induced secondary mechanical hypersensitivity, a common symptom of chronic pain. Here, we aimed to discern whether structured verbal support from a stranger, a situation that perhaps better approximates a clinical context, could attenuate the development of experimentally induced secondary mechanical hypersensitivity and whether attachment styles moderate this effect. Mechanical hypersensitivity was induced using a well-established electrical stimulation protocol, in forty-four healthy female participants who were randomly assigned to either a support group or an alone group. Participants in the support group received structured verbal support from a stranger during the electrical stimulation. The effect of the electrical stimulation on skin conductance level and cortisol responses was measured to examine the role of the sympathetic and HPA systems, respectively. Additionally, cortical responses to mechanical stimulation were measured before, and after the electrical stimulation to assess differences in cortical responses. Findings reveal that verbal support attenuated not only the perceived intensity and unpleasantness of hypersensitivity but also the late part of the cortical response to pinprick stimulation. Attachment anxiety moderated subjective ratings as well as the spread of hypersensitivity and attachment avoidance moderated the subjective ratings. Social support had no impact on stress responses to the electrical stimulation.