Depression / Somatization and Pain Thresholds in Orofacial Pain Subjects

Objectives:, Changes in sensitivity/perception of pain (pain thresholds) have been related to depression and somatization (anxiety). To examine whether any relationship might exist between depression / somatization (anxiety) and pain sensitivity in orofacial pain subjects, we carried out a clinical and instrumental investigation.

Methods:, Fifty-four adults with orofacial pain (12 males, 42 females) consecutively admitted at the same institution were age- and gender-matched with 54 healthy controls. Depression and anxiety were assessed by a standardized questionnaire (SLC-90) and scored according to the De Rogatis criteria. Pain thresholds (perceptive and objective) were detected by using tooth pulp electrical stimulation (constant current/square wave/ bipolar technique).

Results:, When compared to controls, orofacial pain subjects reported higher depression (median 0.92 vs. 0.55, P<0.01; Mann-Whitney test) and anxiety (0.83 vs. 0.42, P<0.01) levels, and lower perceptive pain threshold (17 vs. 14, P<0.05). Both in orofacial subjects and controls a significant negative association was found between objective pain threshold and both depression (Spearman correlation coefficient, r,-0.619 and -0.614, P<0.0001) and anxiety (r, -0.633 and -0.648, P<0.0001). Perceptive pain thresholds were negatively associated with anxiety in orofacial subjects only (r, -0.369, P<0.010). Associations remained statistically significant (P<0.05) also after adjustment for age and gender.

Conclusion:, A relationship exists between depression and anxiety levels with objective pain thresholds both in orofacial and healthy subjects, nevertheless perceptive sensitivity to pain appears to be associated with anxiety in orofacial subjects only.