Personality disorders (PDs) and Axis I disorders, particularly borderline personality disorder (BPD) and major depressive disorder (MDD), have long been established as risk factors for suicidal behavior (e.g., Friedman, Aronoff, Clarkin, Corn, & Hurt, 1983
; McGlashan, 1986
). However, because the base rates of suicide and suicide attempts are relatively low compared to the base rates of these disorders, diagnoses in and of themselves are of limited use in predicting suicidal events. Furthermore, it is not always clear whether improvement or deterioration of a psychiatric condition (particularly MDD) is the greater risk factor for suicidal behavior. Therefore, alternative means of investigating the predictive utility of psychiatric disorders, such as identifying high-risk combinations of co-occurring Axis I and Axis II disorders, or examining specific changes in the course of a disorder prior to a suicide event, may be more effective.
In reviewing suicide research, various types of suicide behaviors need to be distinguished, particularly because each type of behavior is associated with different risk factors. Generally accepted classifications of suicide behavior include completed suicide, suicide attempt, and suicide ideation (Beck, Beck, & Kovacs, 1975
; O’Carroll et al., 1996
). The consistent findings that men are at greater risk for suicide completion and women are at greater risk for suicide attempt(s) (Hirschfeld & Davidson, 1988
) highlight the importance of identifying risk factors specific to the behavior. Nonetheless, because history of past suicide attempt(s) is one of the greater risk factors for suicide completion, research on suicide attempts inevitably informs clinical judgment with regard to suicide completion (e.g., Goldstein, Black, Nasrallah, & Winokur, 1991
; Roy, 1982
). Furthermore, the distinction between suicide attempts and suicide gestures (or parasuicide) has been advocated on the basis of differing intent to die. Specifically, those who make a suicide gesture (or parasuicide) do not intend to die but do aim either to draw attention through their actions, or to regulate their emotions (Kemperman, Russ, & Shearin, 1997
), and have arguably different associated risk factors (Schneidman, 1985
Several studies have examined risk factors for completed suicide among high-risk populations (e.g., psychiatric inpatient samples). McGlashan’s (1986)
Chestnut Lodge study in which BPD patients were monitored for a mean of 15 years and Stone’s (1989)
New York State Psychiatric Institute study in which BPD were monitored for a mean of 16 years found higher rates of suicide among BPD patients with co-occurring major depression. A recent 20-year prospective study found both PDs and MDD were unique significant risk factors for eventual suicide (Brown, Beck, Steer & Grisham, 2000
). However, one 15-year follow-up study failed to find any difference in prevalence rates of affective disorders between BPD patients who committed suicide and nonsuicidal BPD controls (Paris, Nowlis, & Brown, 1989
). Similarly, Kullgren (1988)
found that rates of MDD did not differ between BPD patients who committed suicide and BPD inpatients who did not commit suicide within a month after discharge. Therefore, it remains uncertain as to whether MDD is an immediate or lifetime risk for suicide, and whether it remains a risk factor within the context of BPD.
Similarly, the question of whether co-occurrent BPD/MDD increases one’s risk for suicide attempts beyond the effect of each of these disorders independently, has also been debated. In a prospective follow-up of patients with BPD, other PDs, and no PD, those with BPD continued to be more suicidal 2 to 5 years later, despite no significant differences in rates of mood disorders (Mehlum, Friis, Vaglum, & Karterud, 1994
). Among a large sample of patients with panic disorder who were monitored for 5 years, BPD and MDD were both significant risk factors for suicide behavior (Warshaw, Dolan, & Keller, 2000
). Retrospective studies have generally found that patients with co-occurring MDD/BPD are more likely to have a history of suicide attempts than those with MDD only, or MDD with another personality disorder (Corbitt, Malone, Haas, & Mann, 1996
; Kelly, Soloff, Lynch, Haas, & Mann, 2000
). However, in a study of BPD patients, depressed mood, but not co-occurring affective disorder, was found to be associated with a history of suicidal behavior (Soloff, Lis, Kelly, Cornelius, & Ulrich, 1994
). These results suggest that severity of depressed mood, as assessed subjectively and on a continuum, may be a better predictor of suicide behavior than the MDD diagnosis. Further efforts are necessary, particularly prospective studies, to determine whether MDD remains a significant risk factor when comorbid with BPD, and whether alternative ways of assessing depression may be more useful in predicting suicide attempts.
Other Axis I disorders have also been the focus of investigative efforts to identify risk factors for suicide attempts. These include studies of schizophrenia (Young, et al., 1998
), panic disorder (e.g., Korn, Plutchik, & Van Praag, 1997
), posttraumatic stress disorder (PTSD; e.g., Kessler, Borges, & Walters, 1999
), and substance use disorders (e.g., O’Boyle & Brandon, 1998
). However, for the most part, these disorders are examined independent of PD diagnoses.
Numerous studies have examined presence of Axis I disorders as predictors of suicide attempts, but have yielded inconsistent findings. No study, to the best of our knowledge, has examined course of Axis I disorders as predictors of suicide attempts. The examination of Axis I disorders (selected on the basis of empirically supported associations with suicidal behaviors) as dynamic variables would represent an innovative approach to approximating clinical presentations. We are specifically interested in worsening of Axis I conditions for its clinical relevancy; that is, patients are more likely to seek treatment when their conditions worsen rather than improve. Finally, our examination of these variables in a PD sample allows us to focus on a group that is at particularly high risk for suicidal behaviors.
This investigation examines prospective, longitudinal data in which suicide behaviors, Axis I symptomatology, and PD features were assessed at specified follow-up intervals, as part of a larger study examining the course of four PDs (including BPD). Our design allowed the advantage of examining immediate precipitants and the change in status of a particular Axis I disorder (as opposed to presence or absence of diagnosis) at the time of the suicide attempt. Furthermore, unlike many other studies of suicidal behavior, this sample was not restricted to inpatients or those who were admitted for a previous suicide attempt, but was recruited from a variety of treatment settings. Our first aim was to examine whether the diagnoses frequently associated with suicide behavior (i.e., BPD, MDD, panic disorder, PTSD, and substance use disorders) emerged as significant unique risk factors for suicide attempts. We predicted that these disorders at baseline would be associated with an increased likelihood of a suicide attempt during the 2-year follow-up. Our second aim examined whether worsening in the course of MDD, PTSD, substance use disorders (SUD), and panic disorder, would be a significant predictor for suicide attempts. We predicted that changes in these disorders would predict a suicide attempt.