Patients with a diagnosis of borderline personality disorder are frequently assessed after suicide attempts in our practices, emergency rooms, and crisis intervention services. They have historically been the subject of teaching and papers about the negative countertransference their acts engender, and more recently discussions about whether they should be subsumed into bipolar disorder or posttraumatic stress disorder (PTSD). However, the literature guiding the clinician about risk and risk factors for these patients for both parasuicidal behavior and suicidal attempts and the best practices for treatment still remains sparse. In their article in this month's issue of the Journal (1), Harned et al. have demonstrated that structured research into the phenomenology of this disorder can be done and that such research can glean productive elements for both treating psychiatrists and clinical researchers.

Harned et al. studied 94 patients with borderline personality disorder who had attempted suicide with the past year. One group had a comorbid diagnosis of PTSD (N=53) and the other did not (N=41). These two groups were compared in relation to 1) the severity of the borderline personality disorder, 2) the characteristics of trauma history, 3) elements of suicidal and nonsuicidal self-injury, 4) comorbid axis I disorders, 5) comorbid axis II disorders, 6) emotional regulation and expressivity, 7) psychosocial functioning, 8) mental health treatment utilization, and 9) medical treatment utilization. Differences between the two groups occurred in the fields of lethality, intent, triggers, trauma history, emotional regulation, and axis I comorbidity.

This article is worth careful reading not only for its application of solid clinical research methodology to a very difficult population, but also for its elucidation of the characteristics of these patients, which may have salience to the practicing clinician. Perhaps the most clinically interesting finding was that patients with borderline personality disorder and PTSD have significantly more nonsuicidal acts than patients diagnosed with borderline personality disorder alone. As the authors point out, initial reading of the data suggests that since the proportion of serious self-injury is less in the borderline personality disorder/PTSD group, the risk for serious self-harm is also less. This reading of the data is erroneous, since this percentage is generated from a higher baseline of total events. If we count the number of serious self-injury attempts for both groups, there is no difference. Both patients with PTSD and borderline personality disorder and those with borderline personality disorder only make serious self-injury attempts. We should not be disarmed by the patient, more likely the patient with PTSD and borderline personality disorder, who has many nonlethal parasuicidal "gestures." Their baseline risk for serious self-injury appears equivalent to the risk for the nongesturing patient. Thus, clinical adages about the high probably of lethality, even in patients who have made many nonlethal gestures, is substantiated.

A second finding relates to the nature of the precipitant for suicide attempts. For PTSD/borderline personality disorder patients the precipitant is more likely to be related to interpersonal issues. This finding must pique the treating clinician's interest, as it implies that treatment that focuses on suicide prevention may need to be different for these two groups. Protection for the dually diagnosed woman may need to be shaped more like a relapse prevention model for substance abuse, which must take into account the personal nature of contact with the dealer or even the significance of the location of the drug purchase in the patient's daily life. A similar investigation of the personal triggers and cues for the suicidal patient with borderline personality disorder and PTSD may be effective. Accordingly, subjects with both PTSD and borderline personality disorder appeared more likely to utilize intentional self-injury as a means to influence others. This, too, offers a possible intervention point into the dynamics of such behavior and a possible avenue to tailor more specific interpersonal interventions.

Psychosocial functioning as well as mental health and general medical treatment utilization did not discriminate between the two groups. As the authors point out, there may be a ceiling effect as a consequence of the patients' suicide attempts, with both groups having similarly impaired function and equivalent treatment utilization. Patients with both PTSD and borderline personality disorder had nearly two times as much exposure to unwanted sexual experiences as did the borderline personality disorder group. This is somewhat staggering as even the women with only borderline personality disorder reported an average of 25 lifetime traumatic events!

Patients with both PTSD and borderline personality disorder with suicidal behaviors differed in relation to emotional deregulation and anger suppression suggesting enhanced emotional numbing that typifies the PTSD diagnosis. Interestingly, for these two populations, there was not a finding of difference in the comorbidity of mood disorders, substance use, or eating disorders. Unfortunately, this study did not look at additional social elements of function such as marital status and health, employment, and criminal behavior or conviction.

This study does offer a fairly substantial rebuttal to those who would argue that, due to the high incidence of trauma within the population of patients with borderline personality disorder, borderline personality disorder and PTSD are of the same diagnostic category varying only in intensity. This study suggests that there are qualitative differences in the characteristics of patients with borderline personality disorder only compared with those dually diagnosed with PTSD and borderline personality disorder.

Of course, this study has limitations. In selecting the research population, patients with a psychotic disorder (perhaps the most severe of PTSD patients) or borderline patients with what in the past had been described as micropsychotic episodes were excluded as were patients with bipolar disorder. One could speculate that inclusion of these two populations could markedly shift the total population profiles. These groups also need to be studied.

This is a gender-specific study and is silent (by choice) regarding PTSD and the borderline personality disorder diagnosis in men. While PTSD appears highly associated with borderline personality disorder in women, the paucity of this borderline personality disorder diagnosis in men, despite the substantial incidence of male PTSD, might offer some further understanding of the genesis of borderline personality disorder or protective factors for its manifestation.

This was a highly selected population defined not only by recent suicide attempts, but by solicitation for treatment. How this, too, would skew the findings of a replicate study is yet to be determined.

This article thus expands the horizons of our thinking about what is possible to learn about borderline personality disorder, PTSD, and suicide. First, this research demonstrates that this historically difficult population can be examined with the same methodology used for studying affective illness and psychosis. Such research characterizing borderline personality disorder and its comorbid conditions is long overdue. Second, this study, though in need of replication, demonstrates that our thinking about borderline personality disorder patients (at least women) as a homogeneous population is erroneous. Further work must be forthcoming to understand the subsets of this diagnostic category not only in the context of the risks of self-harm and completed suicide, but also to assess the efficacy of treatment outcomes and whether such outcomes vary positively or negatively depending upon the complexity of the borderline personality disorder and its comorbid conditions, particularly PTSD