The pain paradox: borderline personality disorder features, self-harm history, and the experience of pain.

Individuals with borderline personality disorder (BPD), compared to controls, report a relative absence of acute pain. In contrast, BPD is overrepresented among chronic pain patients, suggesting they experience a relative excess of chronic pain. To date, this "pain paradox" has been only partially explored; no study has examined both acute and chronic pain in the same sample. In addition, previous research has not fully examined the effect of nonsuicidal self-injury (NSSI) on either acute or chronic pain experience in BPD. Undergraduates (N = 206), oversampled for those high in BPD features, completed a Cold Pressor Task (CPT), rating their pain every 15 s over a maximum of 4 min. Following the CPT, participants completed measures of BPD features, NSSI history, past-year pain, and perceived pain tolerance. Results did not support the expected negative association between BPD features and acute pain. Multilevel modeling revealed an interaction of BPD features and NSSI history on CPT pain ratings: Among individuals in the no-NSSI group, BPD features were associated with greater acute pain. Among individuals in the NSSI group, BPD features were not significantly associated with acute pain. Results for past-year pain indicated that BPD features were associated with greater past-year pain regardless of NSSI history. This finding, coupled with the difference in the association of BPD features and acute pain between the NSSI and no-NSSI groups provides tentative evidence that the combination of BPD features and NSSI history, among nonclinical samples, is linked to a pain paradox.