The effects of naltrexone on repressive coping and disclosure of emotional material : a test of the opioid-peptide theory of repression/hypertension

A relationship between hypertension and repression has long been observed in the psychological literature. Those who exhibit repressive coping styles also tend to exhibit elevated blood pressure levels. Classically, this relationship has been explained by emphasizing the role of repression in elevating, through unknown mechanisms, blood pressure. Recent research, however, suggests that the directionality of this relationship may be reversed, and high blood pressure, through baroreceptor-mediated, endogenousopioid activity, may result in repressive phenomena. The present study tests this hypothesis by comparing the disclosure of 8 normotensives and 10 hypertensives after receiving either the opioid antagonist naltrexone or a placebo. Administration of the drug or placebo was double-blind and randomized across 4 laboratory visits. Following absorption of the drug, participants verbally described their mood, conflicts, stressors, and concerns. Following the verbal narrative, participants completed measures of repressive coping style, disclosure, mood, and self-perceptions. To accommodate for the small sample size, planned comparisons were used for analyses. Specifically, the hypothesis was tested that naltrexone would significantly alter dependent measures, in the direction of higher disclosure and less repression, in hypertensive subjects only. Results supported the hypothesis. Significantly greater disclosure and significantly less repression were exhibited by hypertensives in the drug sessions versus placebo sessions. The drug condition had no effect on the self-report of normotensives. The results provide initial evidence for the role of endogenous opioids in repression and hypertension.