Psychosocial factors predict opioid analgesia through endogenous opioid function

Area of Science:

• Pain Management
• Neuroscience
• Psychology

Background:

• Opioid analgesics are commonly used for chronic non-malignant pain.
• Predictors of optimal opioid analgesic efficacy are not well-established.
• Psychosocial factors may influence pain perception and treatment response.

Purpose of the Study:

• To investigate if psychosocial factors predict changes in low back pain after opioid administration.
• To determine if endogenous opioid (EO) function mediates the relationship between psychosocial factors and opioid response.
• To identify potential biomarkers for predicting opioid analgesic efficacy.

Main Methods:

• 89 participants with chronic low back pain (non-opioid users) received placebo, naloxone, or morphine intravenously.
• Pain intensity was assessed before and after drug administration in a counterbalanced design.
• Endogenous opioid (EO) function and opioid analgesic response were indexed by comparing conditions.

Main Results:

• Psychosocial variables positively predicted morphine analgesic responses for low back pain.
• Depressive symptoms, anxiety, pain catastrophizing, and disability were negatively related to EO function.
• EO function negatively predicted morphine analgesic response, and partially mediated the link between psychosocial factors and analgesic response.

Conclusions:

• Psychosocial factors may predict enhanced analgesic responses to opioid medications.
• Deficits in EO function might be associated with greater depressive symptoms, anxiety, catastrophizing, and disability.
• These findings suggest psychosocial factors could help identify patients who benefit most from opioid therapy.