Objective-The first purpose of this study was to determine the rate of use of prescription opioid medication reported by patients with borderline personality disorder (BPD) and to compare that to the rate reported by axis II comparison subjects during a 10-year period of prospective follow-up. The second purpose of this study was to determine the most clinically relevant predictors of prescription opioid use among borderline patients.Method-The medical conditions and axis I disorders of 264 borderline patients and 63 axis II comparison subjects were assessed at six-year follow-up and five contiguous follow-up waves that were two years apart. These assessments were conducted between July 1998 and December 2010. Family history of psychiatric disorder had been assessed at baseline by interviewers blind to the diagnostic status of the subjects. All three areas were assessed using semistructured interviews with proven psychometric properties: the Medical History and Services Utilization Interview (MHSUI), the Structured Clinical Interview for DSM-III-R Axis I disorders (SCID I), and the Revised Family History Questionnaire (FHQ-R).Results-Borderline patients were significantly more likely to report the use of prescription opioid medication over time than axis II comparison subjects (OR=1.79; 95%CI, 1.01-3.17). The best predictors of opioid use among borderline patients were the time-varying presence of back pain (OR=1.95; 95%CI, 1.41-2.70), fibromyalgia (OR=3.29; 95%CI, 1.70-6.36), and osteoarthritis (OR=3.32; 95%CI, 2.08-5.29) as well as a baseline history of drug abuse (OR=1.89; 95%CI, 1.27-2.81).Conclusions-The sustained use of prescription opioids is common among and discriminating for patients with BPD. The results also suggest that these borderline patients may be particularly sensitive to physical pain-mirroring their well-known heightened sensitivity to emotional pain.Address correspondence to Dr. Frankenburg, McLean Hospital, 115 Mill Street, Belmont, Massachusetts 02478; phone: 781-687-3004; fax: 617-855-3580; Frances.Frankenburg@med.va Other problems with opioid medications include side effects such as constipation, drowsiness, and decreased libido. Over time, the analgesic efficacy may not be maintained. 4 Chronic opioid use can also increase sensitivity to pain. 5,6 Ever since the work of Portenoy and Foley, the rates of opioid addiction among pain patients have been thought to be very low. Fishbain et al. 7 reviewed over 67 studies of opioid treatment of nonmalignant pain and found that of 2500 patients just over 3% developed abuse or addiction. The rates were lower if subjects were not treated if they had any current or previous history of abuse or addiction. Urine toxicology, however, revealed a higher number of problems. For example, some patients had no opioids in their urine suggesting possible diversion of these medications. In general, the rates of addiction to prescription opioids are higher if the patient has a history of substance abuse, comorbid mental illness, or somatization, or i...