Study Limitations in Report of Suicidal Behavior Among Women With Co-occurring PTSD and Borderline Personality Disorder
Posted Mar 04 2011 1:30am
Josh Nepon, M.D., Jina Pagura, M.A., and Jitender Sareen, M.D.
Winnipeg, Manitoba, Canada
TOTHE EDITOR: In the October 2010 issue of the Journal, MelanieS. Harned, Ph.D., et al. ( 1 ) reported on an important studyexamining the relationship between posttraumatic stress disorder(PTSD) and borderline personality disorder. This is an importantarea of inquiry, and the authors have done an admirable jobin comprehensively assessing their sample. However, the studyhas several limitations, and the conclusions are not consistentwith recent studies that were not cited.
As stated by Harned et al. ( 1 ) themselves, we want to underscorethe fact that the small size and select nature of their study(94 women) make it difficult to draw conclusions. They conductednumerous comparisons across variables without any adjustmentfor multiple comparisons. Furthermore, they have not cited recentlarge epidemiologic studies examining the association betweenPTSD, borderline personality disorder, and suicide attempts( 2–4 ).
Harned and colleagues' conclusion that frequency, intent, andlethality of suicide attempts are the same for individuals withborderline personality disorder with and without PTSD is inconsistentwith recent work. Cougle et al. ( 2 ), using the U.S. NationalComorbidity Survey Replication data (N=5,692), demonstratedthat PTSD is associated with suicide attempts, even after adjustingfor the effects of borderline personality disorder. We extendedthese findings using the National Epidemiologic Survey on Alcoholand Related Conditions (N=34,653), by showing that PTSD is associatedwith suicide attempts after adjustment for all sociodemographicfactors and axis II disorders ( 3 ). Pagura et al. ( 4 ) were thefirst to examine comorbidity of PTSD and borderline personalitydisorder in a large nationally representative sample by comparingindividuals with PTSD alone (N=1,820), borderline personalitydisorder alone (N=1290), and comorbid PTSD and borderline personalitydisorder (N=643). This study found that individuals with comorbidPTSD and borderline personality disorder had greater odds oflifetime suicide attempt compared to individuals with eithercondition alone ( 4 ).
We have shown that individuals with co-occurring PTSD and borderlinepersonality disorder have higher odds of having a suicide attemptthan either disorder alone ( 3 , 4 ). These findings are in contrastto the findings of Harned and colleagues' study ( 1 ). We believethe discrepancy between the epidemiologic studies and the Harnedet al. study is due to the differences in sample size. We notethat epidemiologic studies cited above are limited by lack ofassessment of lethality of suicide attempts, a strength of Harnedand colleagues' study. We suggest that future clinical studiesneed to gather a larger sample and include a comparison groupof women with PTSD.
The authors report no financial relationships with commercialinterests.
This letter was accepted for publication in December 2010.