Interacting Effects of Trait Anger and Acute Anger Arousal on Pain

Abstract

Objective Elevated trait anger (TRANG; heightened propensity to experience anger) is associated with greater pain responsiveness, possibly via associations with deficient endogenous opioid analgesia. This study tested whether acute anger arousal moderates the impact of TRANG on endogenous opioid analgesia. Methods 94 chronic low back pain participants (LBP) and 85 healthy controls received opioid blockade (8mg naloxone) or placebo in randomized, counterbalanced order in separate sessions. Participants were randomly assigned to undergo either a 5-minute anger recall interview (ARI) or neutral control interview (NCI) across both drug conditions. Immediately following the assigned interview, participants engaged sequentially in finger pressure and ischemic forearm pain tasks. Opioid blockade effects were derived (blockade minus placebo condition pain ratings) to index opioid antinociceptive function. Results Placebo condition TRANG × Interview interactions (p’s<.05) indicated that TRANG was hyperalgesic only in the context of acute anger arousal (ARI condition; p’s<.05). Blockade effect analyses suggested these hyperalgesic effects were related to deficient opioid analgesia. Significant TRANG × Interview interactions (p’s<.05) for both pain tasks indicated that elevated TRANG was associated with smaller blockade effects (less endogenous opioid analgesia) only in the ARI condition (p’s<.05). Results for ischemic task VAS intensity blockade effects suggested that associations between TRANG and impaired opioid function were most evident in LBP participants when experiencing anger (Type × Interview × TRANG Interaction; p<.05). Conclusions Results indicate that hyperalgesic effects of TRANG are most prominent when acute anger is aroused, and suggest that endogenous opioid mechanisms contribute.

Expectancy Effects on Conditioned Pain Modulation Are Not Influenced by Naloxone or Morphine

“…General criteria for participation included age between 18–55; no self-reported history of cardiovascular disease, hypertension, liver or kidney disorders, posttraumatic stress disorder, bipolar disorder, psychotic disorder, diabetes, seizure disorder, or alcohol or drug dependence; no use of anti-hypertensive medications; and no daily use of opioid analgesics (with absence of recent use confirmed via urine opiate screen). As in our past opioid blockade studies [17–19], additional inclusion criteria for the back pain group were chronic daily low back pain of at least 3 months’ duration with an average past month severity of at least 3 on a 0–10 verbal numeric pain intensity scale. Individuals with chronic pain related to malignancy, autoimmune disorders, or fibromyalgia were excluded.…”

Endogenous opioid function mediates the association between laboratory-evoked pain sensitivity and morphine analgesic responses

“…General criteria for participation included age between 18–55; no self-reported history of cardiovascular disease, hypertension, liver or kidney disorders, posttraumatic stress disorder, bipolar disorder, psychotic disorder, diabetes, seizure disorder, or alcohol or drug dependence; no use of anti-hypertensive medications; and no daily use of opioid analgesics (with absence of recent use confirmed via urine opiate screen before each laboratory study session). As in our past opioid blockade studies 7–9 , additional inclusion criteria for the CLBP group were chronic daily low back pain of at least 3 months’ duration with an average past month severity of at least 3 on a 0–10 verbal numeric pain intensity scale. Individuals with chronic pain related to malignancy, autoimmune disorders, or fibromyalgia were excluded.…”

“…As in past work 7–9 , an 8 mg dose in 20 ml normal saline was infused intravenously over a 10-minute period through an intravenous cannula placed in the non-dominant arm. At this dosage, naloxone provides effective blockade of all three major opioid receptor subtypes 34 .…”

“…First, participants underwent an ischemic pain task based on procedures described by Maurset et al 37 , similar to our past opioid blockade studies 7–9 . Participants first engaged in two minutes of dominant forearm muscle exercise using a hand dynamometer at 50% of his or her maximal grip strength as determined prior to beginning the laboratory procedures.…”

The Contribution of Differential Opioid Responsiveness to Identification of Opioid Risk in Chronic Pain Patients

“…The first was a modified ischemic pain task based on that developed by Maurset and colleagues 30 which we have used in our past studies of opioid systems 3,4,7 . Participants first engaged in two minutes of dominant forearm muscle exercise using a hand dynamometer at 50% of his or her maximal grip strength (determined prior to the laboratory procedures), followed by raising their dominant forearm over their head for 15 sec.…”