Risk factors associated with high lethality attempts and completed suicide in BPD include older age, lower SES, social, vocational and financial stressors, similar to other high-risk groups. The role of co-morbid depression or substance use disorders is equivocal, with some studies, though not all, finding a relationship (Soloff 2005
, for review). Are there unique characteristics of BPD which increase vulnerability to suicidal behavior? Cross-diagnostic studies suggest that the borderline patient's high frequency of attempts, impulsive and antisocial behaviors (or ASPD co-morbidity) increase their risk of suicidal behavior. Within
the BPD diagnosis, high lethality attempts are predicted by low SES, comorbidity with ASPD, a high degree of subjective intent to die and long treatment histories. Impulsivity and aggression are ubiquitous within a cohort of BPD subjects and do not discriminate between high and low lethality attempters (Soloff, Fabio, Kelly, Malone & Mann, 2005
). However, impulsivity is significantly related to frequency of attempts and may play an indirect role in high lethality attempts and completion (Chesin, Jeglic & Stanley, 2010
). The interaction
of impulsivity and aggression may contribute to suicide completion in BPD, though this effect is not significant after controlling for Cluster B co-morbidity, (i.e. co-morbid ASPD, found in 92.5% of suicides (McGirr, Paris, Lesange, Renaud & Turecki, 2007
). In the present study, we assessed the predictive association of these risk factors with high lethality attempts and increasing trajectories of attempt lethality over time in an effort to define a poor prognosis subtype of BPD.
Among repeat suicide attempters, we found older age and a history of prior hospitalizations predicted High Lethality attempter status, suggesting that chronicity and illness severity play an important role in the vulnerability to high lethality suicidal behavior. These results are consistent with earlier retrospective studies of completed suicide in patients with BPD, which found greater initial illness severity, prior attempts, more admissions and time in hospital among suicide victims (Soloff, 2005
). The time to maximum attempt lethality among subjects with increasing Lethality Scale scores in our sample was measured in years (mean 8.94 years), but with extreme variance. Studies of completed suicide in BPD report that the duration of the “suicidal process,“ from first unequivocal suicidal communication (by verbal threat and attempt) to death, may be as brief as 30 months (Runeson, Beskow & Waern, 1996
) or as long as 10 years (Paris & Zweig-Frank, 2001
). Suicide completion in BPD tends to occur relatively late in the course of the illness. In their 27 year follow-up study, Paris and Zweig-Frank (2001)
reported that completed suicide occurred at an average age of 37 years. Younger patients with BPD tended to make frequent low lethality attempts as communicative gestures while older patients completed suicide after years of illness.
A subgroup of borderline patients may experience increasing psychosocial impairment as they age, increasing the vulnerability to suicidal behavior (McGlashen, 1986
). Older patients in the CLPS sample (e.g. those recruited at age 35–45 years of age) began to lose
previously achieved psychosocial improvement by the third year of follow-up, reversing the direction of change. From the third through sixth year, the older cohort showed a progressive decline in function and an increase in psychopathology, significantly different from 2 younger, more stable cohorts (Shea, 2009
Good psychosocial functioning was protective in our analysis of attempt lethality, while poor psychosocial functioning was associated with repeated suicide attempts, and a trajectory of increasing attempt lethality over time. Similar findings have been reported in prospective studies of repeat suicide attempters, independent of diagnosis. In a 10 year study of patients admitted following a suicide attempt, Tejedor, Diaz, Castillon & Pericay et.al. (1999)
found that higher GAF scores on admission and at last evaluation were associated with lower probability of repeated suicide attempt and completion. Similarly, Cedereke and Ojehagen (2005)
reported that a low GAF score (i.e. less than 49) one month after an index attempt, predicted recurrent attempts in the ensuing 1–12 months. In a cross-diagnostic study, Kelly, Soloff, Lynch, Haas & Mann, (2000)
found that depressed and non-depressed patients with BPD who were low on social adjustment were 16 times more likely to be suicide attempters than patients with MDD alone. In our longitudinal studies, we noted that poor psychosocial functioning was a prospective predictor of suicide attempts at 1 year, 2 year and 2 to 5 year follow-ups (Soloff and Fabio, 2008a).
How is psychosocial function protective? Kelly (2000)
suggests that good psychosocial function buffers the stress of recent life events in subjects with BPD. Negative life events were significant predictors of suicide attempts among PD subjects in the CLPS analysis (Yen, Pagano, Shea, Grilo, Gunderson, Skodol et al., 2005
). BPD subjects experiencing negative life events, often as a result of their own actions, may lack the psychological, social or financial resources to cope with the ensuing consequences.
Poor psychosocial function remains a risk factor for suicidal behavior in BPD long after acute and temperamental symptoms of the disorder are remitted. The McLean Study found that only half of BPD patients achieved good social and vocational functioning by 10 year follow-up, despite symptomatic improvement in 93% of patients. Among patients who failed to obtain good psychosocial functioning, 93.9% failed because of impaired vocational achievement, not poor social functioning (Zanarini, 2010
). The CLPS analysis found that unstable interpersonal relationships were a significant predictor of poor outcome at two year follow-up, but did not assess vocational achievement (Gunderson, Daversa, Grilo, McGlashan Zanarini, Shea, et.al. 2006
). Our Trajectory analysis suggests that the High Lethality subgroup is characterized by impairment in both
family relationships and work achievement. This is consistent with studies in PD patients which find suicide completion associated with job problems, unemployment, and financial difficulties, but also problems with family relationships, interpersonal loss, separations, and loneliness (Heikkinen, Isometsa, Henriksson,, Marttunen, Aro, Lonnqvist et.al. 1997a,b).
To the best of our knowledge, this is the first reported use of trajectory analysis to characterize patterns of attempt lethality over time. Finding a two class solution suggests that trajectory analysis is a useful statistical tool to identify BPD subtypes relative to suicidal behavior. Subjects with the High Lethality trajectory were characterized by inpatient recruitment (an indirect measure of illness severity), and poor psychosocial functioning compared to those with Low Lethality trajectories. Convergent results in our regression and trajectory analyses suggest that the patient at highest risk for suicide may be older, with greater illness severity, vocational failures, and estrangement from family and friends. Low Lethality subjects had better overall psychosocial functioning but more Negativism, lifetime substance abuse and Cluster B histrionic and /or narcissistic PD co-morbidity. We speculate that the attempts of this group may reflect dramatic “communicative gestures,” which show little change in medical lethality with repeat attempts.
Attempters are not completers, but overlapping populations (Maris, Berman & Silverman, 2000
). Although a history of prior attempt is a strong predictor of repeat attempts and completion, predictors based on attempt behavior may not apply directly to patients who complete suicide. The same may be true of subtypes defined by attempt behavior. Characteristics of High Lethality attempters with BPD resemble those of suicide completers (Soloff, 2005a).
Several negative findings are noteworthy. We found no significant role for MDD or measures of depressed mood as predictors of attempt lethality or characteristics of BPD subtypes related to lethality. The association of co-morbid MDD with suicidal outcomes in BPD is inconsistent in the literature (Soloff, 2005 b). Large, epidemiologic studies find that mild depressive syndromes (e.g. depression nos), but not MDD, are common in PD patients who complete suicide (Isometsa, Henriksson, Heikkinen, Aro, Marttunen, Lonnqvist et al., 1996
). The prevalence of MDD among BPD patients may diminish over time, perhaps reflecting the efficacy of treatment or natural history of the disorder (Paris & Zweig-Frank, 2001
). In our longitudinal studies of suicidal behavior in BPD, we used Cox proportional hazards models to identify baseline predictors of medically significant suicide attempts at 1 year, 2 years, and 2–5 year follow ups. MDD was a prospective predictor of suicide attempts in BPD in the first year following assessment, but not at 2 years and beyond. “Outpatient treatment” (prior to any attempt in the interval) was significantly associated with decreased risk of a suicide attempt in the 12 month follow-up, and in the 24 – 60 month follow-up intervals. i.e. Treatment was protective (Soloff & Fabio, 2008
We found no predictive associations between attempt lethality and measures of impulsivity (BIS), aggression (LHA), or ASPD co-morbidity. Impulsive-aggression is associated with attempt behavior across diagnoses (Mann, Waternaux, Haas & Malone, 1999
), and in patients with affective disorders (Oquendo, Galfalvy, Russo, Ellis, Grunebaum, Burke et al., 2004
). ASPD is associated with high lethality attempts in subjects with BPD (Soloff, 2005a), and Cluster B co-morbidity (primarily ASPD with impulsive-aggression) with completed suicide (McGirr, Paris, Lesage, Renaud & Turecki, 2007
). Impulsive-aggression is a defining characteristic of BPD, ubiquitous within a BPD sample, and did not predict degrees of attempt lethality in our previous retrospective or prospective studies (Soloff, 2005
; Soloff, 2008
). Increased numbers of subjects and suicide attempts are needed to further refine the trajectory analysis, and will result in a more detailed description of BPD subtypes in relation to suicidal behavior.