Dear Editor:
According to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), suicidal behavior, gestures, and/or threats are characteristic features of borderline personality disorder (BPD). However, some research suggests the possibility of different symptom manifestations of BPD as a function of treatment setting.[1] If so, then suicide attempts might not be associated with BPD in such patients from various medical settings. As for previous work in this area, in a sample of gastric surgery candidates, we found that those with suicide attempts were approximately four times more likely to evidence BPD than those without such histories.[2] In addition, data indicate that patients with BPD develop reasonably high rates of medical problems over time, suggesting drift of BPD patients from psychiatric settings into medical settings,[3,4] thereby enhancing the relationship between suicide attempts and BPD in a medical population. In this study, we examined the relationship between suicide attempts and BPD symptomatology in a sample of cardiac-stress-test patients to determine if this clinical feature of BPD transcends the psychiatric setting.

Participants were consecutive patients, ages 18 years or older, male or female, undergoing cardiac stress testing in a community hospital from June 6, 2010 to September 3, 2010. Exclusion criteria were medical (e.g., pain), psychiatric (e.g., psychosis), cognitive (e.g., dementia), or intellectual difficulties that would preclude the successful completion of a survey. Two recruiters approached 302 candidates and enrolled 251 participants, for a response rate of 83.1 percent.

Among the 251 participants, 250 completed study measures. Of these, 117 were male and 133 female, who ranged in age from 20 to 91 years (M=58.02, SD=13.88). The large majority was White (93.2%), followed by Black (3.2%), Native American (1.6%), Other (1.2%), and Asian (0.4%). One respondent (0.4%) did not indicate ethnicity. With regard to educational attainment, 19 (7.6%) had not finished high school; 73 (29.2%) had only a high school diploma; 73 (29.2%) attended college but had no degree; 12 (4.8%) had earned a two-year college degree, 31 (12.4%) earned a four-year collegedegree, and 39 (15.6%) had earned a graduate degree. Three respondents (1.2%) did not indicate their educational attainment.

Following an explanation of the research project and the signing of consent forms, each participant completed a survey booklet that explored the following: 1) demographic information, 2) past history of suicide attempts (“Have you ever intentionally or on purpose attempted suicide?”), and 3) BPD according to the borderline personality scale of the Personality Diagnostic Questionnaire for the DSM-IV (PDQ-4),[5] a validated, nine-item, true/false, self-report measure that consists of the diagnostic criteria for BPD that are listed in the DSM-IV. A score of 5 or higher is highly suggestive of BPD.

This project was approved by the Institutional Review Boards of the hospital and university, and all participants signed consent forms for participation.

Of the 250 respondents, 15 endorsed a history of attempted suicide. In assessing BPD, we excluded the suicide item from the calculation of the overall score on the PDQ-4. However, we maintained the standard cut-off score for BPD for this measure (i.e., 5), making our analyses more conservative (less probability of false positives). Of the 13 respondents who exceeded the PDQ-4 clinical cut-off score for BPD (i.e., a score of ?5), three (23.1%) indicated having attempted suicide, compared to 12 of the 237 in the BPD-negative group (i.e., a score of <5; 5.1%), c2=7.09, p<0.05. Age was not statistically significantly predictive of history of attempted suicide (Wald=1.29, p<0.26), whereas BPD status was (Wald=10.42, p<0.001).

In this cardiac-stress-test sample, suicide attempts were statistically significantly more common in those with borderline personality symptomatology than in those without such symptomatology. Like our study in gastric surgery candidates, those with suicide attempts in this medical population were approximately four times more likely to evidence borderline personality symptoms.
This study has a number of potential limitations, including the self-report nature of the data. However, this is one of the few studies to examine suicide attempts and BPD in a nonpsychiatric clinical population. According to the present findings, attempting suicide may be a ubiquitous clinical feature among BPD patients in either psychiatric or medicine settings—a finding that is particularly relevant for consultation/liaison professionals.

Acknowledgments
Brandi Palmer, MS, and Michele Jewell, MA, Kettering Medical Center, Kettering, Ohio. There was no funding for this study.

References
1. Sansone RA, Sansone LA. Borderline personality: different symptoms in different settings? Int J Psychiatry Clin Pract. 2003;7:187–191.
2. Sansone RA, Wiederman MW, Schumacher D, et al. The relationship between suicide attempts and borderline personality in gastric surgery candidates. Prim Care Companion J Clin Psychiatry. 2011;13:e1
3. Frankenburg FR, Zanarini MC. The association between borderline personality disorder and chronic medical illnesses, poor health-related lifestyle choices, and costly forms of health care utilization. J Clin Psychiatry. 2004;65:1660–1665.
4. Frankenburg FR, Zanarini MC. Personality disorders and medical comorbidity. Curr Opin Psychiatry. 2006;19:428–431.
5. Hyler S. Personality Diagnostic Questionnaire-4. New York, NY: New York State Psychiatric Institute; 1995.

With regards,
Randy A. Sansone, MD; Nathaniel Dittoe, MD; Harvey S. Hahn, MD; and Michael W. Wiederman, PhD
Dr. Sansone is a professor in psychiatry and internal medicine at Wright State University School of Medicine in Dayton, Ohio, and Director of Psychiatry Education at Kettering Medical Center in Kettering, Ohio. Dr. Dittoe is a fellow in the department of cardiology at Kettering Medical Center in Kettering, Ohio. Dr. Hahn is an associate professor in the department of internal medicine at Wright State University School of Medicine in Dayton, Ohio, and is the Director, Cardiovascular Fellowship Training Program, and Director, Cardiac Noninvasive Laboratory, at Kettering Medical Center in Kettering, Ohio. Dr. Wiederman is a professor in psychology at Columbia College in Columbia, South Carolina.