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Purpose The present study aimed to assess the influence of personality traits on the variability of sensitivity to pain in two distinct groups of healthy subjects with low versus high sensitivity to pain (LSP vs HSP, respectively). Methods Healthy subjects (n=156) were allocated to two groups according to their tolerability to cold stimulation (cold pressor test, CPT, 1°C). Group LSP (n=76) reached the cut-off time of 180±0 sec, and a size matched group of HSP (n=80) tolerated the CPT for an average of 10.5±3.4 sec only. Subjects from both groups completed the self-reported pain sensitivity questionnaire (PSQ), the Pain Catastrophizing Scale (PCS), and the Neuroticism Extraversion Openness - Five Factor Inventory (NEO-FFI). Results In comparison to the LSP group, HSP individuals had higher scores of PSQ ( p <0.001), catastrophizing ( p =0.001), and extraversion ( p =0.01). By adjusting for age and gender, mediation analyses revealed that catastrophizing mediated the relationship between neuroticism and pain sensitivity, both in the allocation of subjects to a certain group of sensitivity to pain (LSP or HSP, B=0.02 95% CI: 0.006–0.040) and in the PSQ score (B=0.01 95% CI: 0.001–0.023). Conclusion These results, which were demonstrated by two different prisms (CPT and PSQ), point to the potential of the five-factor inventory and pain catastrophizing scale as tools for identifying specific personality traits associated with a high sensitivity to pain.

Associations between psychological dispositions and adverse childhood experiences (ACEs) tends to vary by ACE category (i.e. childhood abuse, childhood neglect, family dysfunction), particularly for adults with high ACE scores (>4 on a 0-10 scale). Psychological dispositions (such as pain catastrophising, hope, resilience), however, have typically been examined as intermediary factors rather than endpoints (i.e. dependent variables) on mostly adult patients. In this cross-sectional study on healthy adults who completed self-report questionnaires, we hypothesised that even with low ACEs scores (≤4 ACEs), adults with childhood abuse (compared to childhood neglect and family dysfunction, and no ACEs) will have higher pain catastrophising and lower resilience and hope. In healthy adults (n = 47), multivariate analysis of covariance (MANCOVA) indicated that ACE categories and gender were associated with the three dispositions (Pillai's F (6,84) = 2.518, p = 0.027, η 2 = 0.152). Univariate results revealed an association between childhood abuse versus no ACEs and pain catastrophising (Pillai's F (2,43) = 7.084, p = 0.002, η 2 = 0.248). No associations were found between the ACEs categories and hope or resilience. Among healthy adults with few ACEs, history of childhood abuse was uniquely associated with pain catastrophising. Although a sensitive topic, assessing history of childhood abuse would enable health professionals to provide proactive interventions reducing harmful reactions to pain, such as pain catastrophising.

Background The representation of variability in sensitivity to pain by differences in neural connectivity patterns and its association with psychological factors needs further investigation. This study assessed differences in resting-state functional connectivity (rsFC) and its association to cognitive-affective aspects of pain in two groups of healthy subjects with low versus high sensitivity to pain (LSP vs. HSP). We hypothesized that HSP will show stronger connectivity in brain regions involved in the affective-motivational processing of pain and that this higher connectivity would be related to negative affective and cognitive evaluations of pain. Methods Forty-eight healthy subjects were allocated to two groups according to their tolerability to cold stimulation (cold pressor test, CPT, 1°C). Group LSP (N = 24) reached the cut-off time of 180±0 sec and group HSP tolerated the CPT for an average of 13±4.8 sec. Heat, cold and mechanical evoked pain were measured, as well as pain-catastrophizing (PCS), depression, anxiety and stress (DASS-21). All subjects underwent resting state fMRI. ROI-to-ROI analysis was performed. Results In comparison to the LSP, the HSP had stronger interhemispheric connectivity of the amygdala (p = 0.01) and between the amygdala and nucleus accumbens (NAc) (p = 0.01). Amygdala connectivity was associated with higher pain catastrophizing in the HSP only (p<0.01). Conclusions These findings suggest that high sensitivity to pain may be reflected by neural circuits involved in affective and motivational aspects of pain. To what extent this connectivity within limbic brain structures relates to higher alertness and more profound withdrawal behavior to aversive events needs to be further investigated.