Open AccessStress and pain: modality-specific opioid mediation of stress-induced analgesia
Author(s) -
Mustafa Al’Absi,
Motohiro Nakajima,
Stephen Bruehl
Publication year - 2021
Publication title -
journal of neural transmission
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 110
eISSN - 1435-1463
pISSN - 0300-9564
DOI - 10.1007/s00702-021-02401-4
Subject(s) - naltrexone , endogenous opioid , opioid , cold pressor test , placebo , psychology , stressor , medicine , opioid peptide , anesthesia , mediation , blockade , psychiatry , heart rate , blood pressure , receptor , alternative medicine , pathology , political science , law
Preclinical research has demonstrated that exposure to acute stress is associated with attenuated pain perception, so called stress-induced analgesia (SIA). Mechanisms of SIA in humans have not been reliably demonstrated. This study examined the role of the endogenous opioid system in the impact of combined interpersonal and mental stressors on evoked pain responses in 84 participants (34 women). Using a within-subject, double-blinded, counterbalanced design, participants were administered either oral placebo or the opioid antagonist naltrexone (50 mg) across two testing sessions. In each session, they experienced two evoked pain stimuli (cold pressor test [CPT], heat pain) after an extended rest period (rest condition) and after exposure to an acute stressor (a combination of public speaking and mental arithmetic challenge; stress condition). Results showed that both stress and opioid blockade produced significant changes in hormonal and cardiovascular measures, consistent with successful induction of acute stress. Stress was associated with attenuated pain perception (SIA) as indicated by significantly increased CPT tolerance. These effects were particularly pronounced in individuals experiencing the stress condition first. More importantly, SIA effects on CPT tolerance were abolished by opioid blockade. There were no significant SIA effects on heat pain responses. This study demonstrates that the endogenous opioid system may mediate effects of acute stress on pain perception, although this effect seems to be qualified by the type of evoked pain stimuli experienced.