Traumatic Life Experience and Pain Sensitization: Meta-analysis of Laboratory Findings

Area of Science:

• Psychology
• Neuroscience
• Pain Research

Background:

• Psychological trauma frequently co-occurs with pain, but research findings on this relationship using laboratory pain measures have been inconsistent.
• Previous studies often used limited definitions of trauma (e.g., post-traumatic stress disorder) and pain (e.g., pain thresholds), potentially contributing to mixed results.
• Existing reviews may not adequately represent trauma experiences in non-clinical populations, limiting the generalizability of findings.

Approach:

• A systematic review was conducted on the relationship between psychological trauma (including accidents, assault, and abuse) and laboratory pain sensitivity (assessed via quantitative sensory testing).
• The study evaluated the direction of the trauma-pain sensitivity link and explored moderation by pain mechanisms like pain detection, suprathreshold pain, central sensitization, and inhibition.
• Data from 48 studies, yielding 147 effect sizes, were analyzed using a multivariate random-effects model.

Key Points:

• A small but statistically significant positive association (g=0.24) was found between psychological trauma and enhanced laboratory pain sensitivity.
• The relationship was primarily driven by effects on pain detection (g=0.28) and central sensitization (g=0.22).
• While effect sizes were comparable across moderators, significant effects were not observed for suprathreshold pain or inhibition.

Conclusions:

• The findings demonstrate a consistent pattern of trauma-related enhancement of pain sensitivity.
• Central sensitization emerges as a key underlying neurobiological mechanism linking psychological trauma and pain.
• This research provides a more comprehensive understanding of the trauma-pain relationship, including in broader populations.