THE PSYCHOBIOLOGY OF HOSTILITY - POSSIBLE ENDOGENOUS OPIOID MECHANISMS

This study examined the role of endogenous opioids in the relation bet ween hostility and cardiovascular stress responsiveness. Forty-six men completed the Cook-Medley Hostility Scale, and experienced a laborato ry pain stressor once under opioid blockade and once under placebo. Ho stility scores were significantly related to the magnitude of change i n cardiovascular reactivity/recovery resulting from opioid blockade. L ow scorers on the Cynicism subscale displayed increases in heart rate (HR) reactivity under blockade relative to placebo, with reactivity de creases noted in high scorers. Low Hostile Affect scores were similarl y associated with impaired diastolic blood pressure recovery under opi oid blockade. HR recovery results were somewhat different, with high s corers on Aggressive Responding and the total Cook-Medley displaying i mproved HR recovery under opioid blockade, with no change noted in low scorers. These data provide preliminary support for the hypothesis th at low hostile individuals rely on endogenous opioids for buffering ca rdiovascular stress responsiveness, but high hostiles do not.