In clinical populations, the suicide rate of patients with borderline personality disorder (BPD) is estimated between 8% and 10%, a rate far greater than that in the general population. While suicidal tendencies in BPD patients is a multi-determined phenomenon, a key factor that leads to the higher than average mortality rate could be the impulsive trait common among BPD patients. Hence, a general consensus highlights that by reducing the impulsive personality characteristic, this will ultimately reduce the high risk nature of this disorder. In light of this, Dialectical Behavioural Treatment (DBT) – an adapted version of cognitive behavioural therapy – was developed to specifically reduce suicidality in BPD patients by applying behavioural techniques to control impulsivity. This essay reviewed previously conducted randomised controlled trials, to investigate the efficacy of DBT in treating suicidality in BPD patients through reducing impulsivity, as well as examined the limitations of this intervention. The findings indicated DBT to be more effective in several outcome measures, namely self-harm, parasuicidal behaviours and suicidal ideation, when comparing DBT with treatment as usual and community treatment by experts. Additionally, DBT’s mindfulness module was found to be a salient component in reducing impulsive self-injurious behaviour. While the efficacy of DBT is undisputed, this intervention is still an extensive and costly treatment. Hence, dismantling studies were conducted to identify the treatment component most significant to treat suicidality in BPD and findings revealed shortened variants of DBT are more cost-effective and are just as effective in yielding significant improvements.
INTRODUCTION
Suicide risk is a frequent companion in the treatment of Borderline Personality Disorder (BPD); a disorder that has a prevalence of 1-2% in the general population, and is present in 10% of psychiatric outpatients and 20% of inpatients (Lieb, et al., 2004). According to a study conducted by the Substance Abuse and Mental Health Services (SAMHSA) in 2014, nearly 80% of individuals with BPD report a history of suicide attempts and up to 10% do end up completing suicide – a rate that is almost 50 times higher than in the general public (Sack, 2015). In fact, self-harm and suicide attempts are so prevalent in BPD that it is the only personality disorder to have such behaviours included in its diagnostic criteria. For instance, the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) includes “recurrent suicidal behaviour, gestures, or threats, or self-mutilating behaviour’’ as the fifth criterion for diagnosing BPD (Oldham, 2006, p. 20). Indeed, there is an increasingly important need to reduce the high mortality rates of this disorder and debunk the notion of BPD as “the suicidal personality disorder” (Pompili, et al., 2005, p. 319). Given the high risk nature of this disorder, it is important to discern which factors might increase the likelihood of suicide attempts among BPD patients in order to improve our methods of intervention. Hence, rather than just looking at external causal factors such as comorbidity, it is critical to also evaluate the individual characteristics of BPD that is associated with suicidal behaviour, such as impulsivity. Dialectical Behaviour Therapy (DBT) emerged as a one of the only structured psychotherapeutic programme that prioritises decreasing suicidality in BPD patients, by applying behavioural techniques that are targeted at controlling impulsive tendencies. Since its inception, DBT has been established as the primary treatment for suicidal BPD patients due to the large number of randomized controlled trials (RCTs) conducted on it compared to other treatments. In this essay, I will examine the strength of the evidence highlighting the efficacy of DBT in treating impulsive suicidal behaviours in BPD patients, as well as explore the limitations of this intervention.
DEFINITION OF BPD
DSM-IV-TR characterises patients with BPD as having a “pervasive pattern of instability of interpersonal relationships, self-image, and affects, and marked impulsivity”, the diagnosis is determined when at least five of the nine diagnostic criteria are present in an individual (Oldham, 2006, p.20). The cause of BPD symptoms are thought to stem from an interaction between genetic factors and adverse childhood experiences. Social factors such as physical and sexual abuse during childhood as well as intrafamilial trauma (e.g. violence, neglect and losses) have been specifically associated with the diagnosis of BPD and may build the foundation for dysfunctional behaviours and psychological deficits present in patients (Gado, 2016). BPD patients come across as impulsive risk-takers, and being temperamental, which may result in angry outburst and overreactions. Consequently, these characteristics frequently lead to volatile interpersonal relationships being formed with people in their lives (Sack, 2015). Clinical signs of the disorder commonly include emotional dysregulation and impulsive aggressions; however, the most useful indication for a correct diagnosis is repeated self-injury or chronic suicidal tendencies (Lieb, et al., 2004). Patients with this complex illness also usually meets DSM criteria for other psychiatric disorders.
Numerous studies revealed that comorbidity in patients with BPD is a common occurrence. In fact, Soloff and colleagues (2005) found that suicide attempts in patients with comorbidity resulted in higher levels of lethality compared to patients that experience BPD on its own. The high rates of suicide in patients with comorbid BPD suggest that the self-destructive behaviour of these patients may not predominantly be due to the personality disorder itself, but instead be triggered by a secondary coexisting psychiatric disorder. For instance, an experiment comparing suicidal behaviour between BPD and comorbid BPD and major depressive episode, resulted in the latter generating a greater frequency of suicide attempts and a higher degree of lethal intent (Soloff, et al., 2000). By the same token, increased suicide attempts were exhibited in patients with a comorbid BPD and antisocial personality disorder compared to those without such comorbidity (Soloff, et al., 1994). While comorbidity of BPD with other high risk disorders may be a possible causal factor to suicidality, there is still insufficient information available to deduce whether particular combinations of disorders correlate with a higher lethality of suicidal behaviour. Additionally, comorbid BPD does not offer an explanation for the high mortality rates still present in individuals with BPD alone.
Other than external factors, features often found to be consistent with suicide risk in most psychiatric populations are individual personality traits, such as impulsivity and aggression, hence Brodsky and colleagues (1997) proposed that these characteristics also effect suicidal behaviour in BPD. Yen, et al. (2009) aimed to determine whether facets of impulsivity (e.g. urgency, lack of perseverance and lack of premeditation) could be predictor variables of suicide attempts over a seven-year follow-up evaluation. They used an interview rating system to collect data from a personality disorder sample to observe the course of the disorders – including suicidal behaviours – and ran correlation analyses between the predictor variables. The evaluation of impulsivity facets showed that lack of planning and premeditation was significantly associated with suicide attempt status. In my view, an important point to note is that Yen’s, et al. (2009) study measured impulsivity through self-harm and substance abuse. If these components were to be removed and tested individually, it could possibly reveal that these aspects specifically may be the predictors of suicide attempts rather than an impulsive character personality. Hence, a multivariate analysis should be conducted in further studies to asses if that is the case.
An experiment that did control for substance abuse was Brodsky’s, et al. (1997) study that investigated the relationship between characteristics of BPD and suicidal behaviour. The study highlighted that impulsivity and anger dysregulation traits, formed from abusive childhood experiences, could develop into self-destructive behaviours in adulthood. Brodsky and colleagues (1997) gathered lifetime history information of suicidal behaviour from 214 BPD patients that were diagnosed through DSM-III-R structured clinical interviews, and examined the DSM-III-R criteria met with several measures of suicidal behaviour (number of previous attempts, lethality, and intent associated with most lethal attempt). Although none of the BPD criterion significantly correlated to lethality and intent associated with most lethal attempt variables, their findings revealed a relationship between the single trait of impulsivity and the number of previous suicide attempts. The impulsive criterion was associated with a higher number of past suicide attempts in BPD patients, even after control for lifetime prevalence of major depression and substance abuse, and therefore may be a putative risk factor for future suicide attempts. Suicidal behaviour in BPD is generally agreed to be a multi-determined phenomenon; however, both studies demonstrated that the impulsive criterion rather than the all-encompassing severity of the BPD pathology is associated with suicidal behaviour. This association provides promising evidence that reducing impulsivity in BPD patients may be favourable approach to prevent suicide attempts.
DIALECTICAL BEHAVIOUR THERAPY (DBT)
DBT was initially established for the treatment of suicidal patients and was subsequently refined for the treatment of suicidality in BPD patients. In 1991, Marsha Linehan developed DBT because her highly suicidal patients were not responding to standard cognitive-behavioural therapy (CBT) treatments; hence, Linehan was prompted to enhance CBT’s effectiveness by integrating the concept of dialectics and validation strategies (Choi-Kain, Albert & Gunderson, 2016). Dialectics is a philosophical concept involving the dilemma of conflicting opposites; dialectical tension occurs when an initial idea (thesis) is opposed by a conflicting idea (antithesis). In the case of BPD, dialectical tension arises because self-injurious behaviour is both functional (helps patient temporarily reduce distress) and dysfunctional (generates negative impacts on health and is associated with suicide risk) (Salsman & Linehan, 2006). This dialectical tension is reconciled by forming a new idea (synthesis) that helps patients reduce distress without producing negative effects. Additionally, Linehan maintained the importance of validation strategies; affirming the patients’ experience and symptomatic reason would motivate and encourage patients to change detrimental behaviours (Salsman & Linehan, 2006). DBT helps patients find the synthesis to their behavioural dilemmas with the hope that patients will feel both validated and learn more skillful behaviours.
DBT achieves this synthesis through a multimodal skill training programme that emphasises skill training in aspects BPD patients find difficult to accomplish, namely, distress tolerance, mindfulness, emotion regulation, and interpersonal effectiveness. Such skills are lacking in an emotionally sensitive individual with BPD, yet are crucial for these patients to manage “invalidating” environments (i.e. environments that do not accommodate the sensitive individual’s special needs and may elicit destructive thoughts or behaviours) (Choi-Kain, Albert & Gunderson, 2016). DBT treatment offers an extensive intervention that is divided into 4 components; individual therapy, group skills training, between-session telephone coaching, and a therapist consultation team which are all aimed at equipping BPD patients with the previously mentioned skills (Linehan, et al., 2015). The overarching goal of DBT is to help patients develop a different outlook on life by transforming negative thinking patterns and destructive behaviours into positive outcomes. In other words, DBT aims to reduce BPD symptoms but also help patients develop a fulfilling life such that the option of suicide is no longer desirable (Chugani, Seiler & Goldstein, 2017).
EFFICACY OF DIALECTICAL BEHAVIOUR THERAPY IN RANDOMISED CONTROLLED TRIALS (RCT)
Linehan and colleagues (1991) conducted the first RCT by randomly assigning chronically parasuicidal BPD patients to two treatment groups to test the effectiveness of DBT. Due to the treatment lasting one year, it was difficult to select a control group as a no-treatment control group would prove unethical for suicidal patients, and there were no empirically supported psychotherapies present at the time to compare. As a result, the study used “treatment as usual” (TAU) in the community as a control to allow a naturalistic follow-up throughout the year of parasuicidal individuals with BPD. The overall sample was well-chosen as 44 subjects were matched on their history of parasuicide and psychiatric hospitalization, as well as current clinical prognosis, and then equally assigned to a treatment condition. The pre-treatment similarity between DBT and control subjects, as well as the randomized assignment to treatment groups ensured that the results could not be interpreted based on known pre-existing differences (Linehan, et al., 1991). The subjects were assessed at quarterly intervals throughout the year and results found that subjects who received DBT had a median of 1.5 parasuicide acts per year compared with nine acts per year for control subjects. There was also a significant reduction in the medical risk of parasuicidal behaviour as well as frequency of psychiatric hospitalisation and lengths of stay, among DBT patients compared to the control group (Linehan, et al., 1991). Hence, the first RCT clearly demonstrated a treatment effect and showed the effectiveness of a dialectical approach compared to TAU. However, I noted that although the RCT was highly controlled, it would be difficult to generalise towards the population due to the homogenous female nature of the sample.
Four similar RCTs were later carried out to replicate Linehan’s, et al. (1991) study and subsequently, provided further support the efficacy of DBT (e.g. Linehan, Heard & Armstrong, 1993; Linehan, Tutek, Heard & Armstrong, 1994; Turner, 2000; van den Bosch, Koeter, Stijnen, Verheul & van den Brink, 2005) but this essay will discuss three that were conducted in non-research clinical settings. Specifically, Koons’s, et al. (2001) study employed a tighter control variable by standardising TAU whereby all patients received their treatment in the same medical centre rather than at their own local centres as conducted in Linehan’s original study. The study found similar results to Linehan, et al. (1991) whereby DBT patients improved more than TAU patients in terms of suicidal ideation, number of parasuicides and number of hospitalizations. However, I noted a major limitation whereby there was only 10 participants in each condition and they were once again all female; hence, limiting the ability to generalise from the study on top of reducing the statistical power. Additionally, in contrast to Linehan’s, et al. (1991) study, not all patients were parasuicidal at pre-treatment as required by the former study. Koon’s study revealed decreases in hopelessness and depression, unlike Linehan’s (1991) study, which could be due to Koon’s less parasuicidal sample being more amenable to change. Nonetheless, despite its small size, this study still showed improvements in the suicidal symptoms of BPD, as well as suggests that the treatment is not limited to only improving parasuicidal behaviour but could also improve other symptoms such as negative thinking patterns in BPD patients.
Moreover, in Verheul, et al. (2003)’s study, patients in the DBT group received 12-months of therapy, according to the DBT manual, by trained psychologists while TAU consisted of two clinical management sessions a month from the patients’ referral source (e.g. addiction treatment centres or psychiatric services). They found that DBT group generated a greater reduction in self-damaging impulsive acts compared to TAU. In fact, their results indicated that TAU patients’ progress deteriorated over time, suggesting that non-specialised treatment could prove detrimental rather than beneficial. Verheul and colleagues (2003) also examined if the efficacy of DBT would be modified by the baseline severity of parasuicidal acts, and found that DBT had a more profound impact on reducing the frequency of self-mutilating behaviours in participants with a higher baseline but showed similar improvements as TAU on patients in the low-severity group. This suggests that DBT should – consistent with its original aims (Linehan, 1991) – be the intervention of choice for only chronically parasuicidal BPD patients. Overall, both Koons, et al. (2001) and Verheul, et al. (2003) showed that DBT is an efficacious treatment for high-risk behaviours and can be conducted with fairly good adherence by a group of therapists at a location independent of the treatment developer. Hence, these studies lend support to the accumulating evidence that mental health professionals outside academic research centres can effectively learn and conduct DBT.
Another key follow-up study was carried out to determine whether the success of DBT was attributed to treatment factors that were common to most psychotherapies conducted by experts instead of the unique DBT treatment itself. Linehan’s, et al. (2006) RCT replicated the original study (Linehan, et al.,1991) but introduced a rigorous control condition known as community treatments by experts (CTBE) that was designed to maximise internal validity and control for factors previously uncontrolled for in TAU conditions. CTBE is distinct from TAU conditions whereby the characteristics of CTBE therapists are controlled for the study via selection of therapists and supervisory arrangements. CTBE therapists were experts in treating high-risk clients and were categorised into six groups based on treatments they would usually provide BPD patients (the groups ranged from “behavioural therapist” to “very non-behaviroural”). Linehan’s, et al. (2006) study revealed that DBT surpassed the efficacy of CTBE in preventing suicide attempts by reducing it by half compared with the latter. Additionally, DBT was more effective in reducing inpatient psychiatric hospitalisation and had a significantly greater treatment retention. These results suggest that DBT may be uniquely effective in treating suicidal BPD individuals and its success is not solely due to the general features linked to receiving expert psychotherapy care.
Impulsivity seems to be a key traits of BPD that triggers parasuicidal acts; hence, perhaps the efficacy of DBT is attributed to the control of these impulsive tendencies. Impulsive self-harm behaviours act as coping mechanisms for BPD individuals to manage invalidating environments and deal with life sufferings, by lessening the emotional pain, and may additionally help communicate emotional pain to others and elicit help (Ivanoff, et al., 2001). In DBT, mindfulness skill training may be the most salient component as it specifically teaches adaptive emotion regulation skills, that consequently reduces impulsivity. Mindfulness module was designed to balance emotions with reasoning, and teach patients to possess emotional clarity and awareness, instead of acting on impulses and emotion-driven behaviours when distressed (Soler, et al., 2012). Jamilian and colleagues (2014) examined DBT’s success in emotion regulation by specifically evaluating the effectiveness of DBT in reducing impulsivity. They enlisted the valid Baratt Impulsive Scale to measure different types of impulsive behaviours pre- and post-treatment and the results clearly indicated reduction in impulsive behaviour points after participants underwent DBT. The study showed the success of DBT in attenuating impulsivity and may reflect the effectiveness of this therapy in lessening impulsive suicidal behaviours in BPD patients.
LIMITATIONS OF IMPLEMENTING DBT?
The efficacy of DBT in reducing suicidal tendencies of BPD patients remains undisputed; however, due to the costly nature of the intervention, it is important to deduce which components of DBT are essential and to what extent adherence to the DBT manual is required to achieve comparable results to the above studies. BPD individuals take up more mental health resources than most psychiatric disorders, due to the substantial treatment needed to combat the high mortality rate this disorder carries. The standard DBT treatment is highly specialised and expensive, as it requires intensive training and clinical resources. The combination of individual therapy, group skills training, telephone coaching and a therapist consultation team amounts to a minimum of 3-4 hour long treatments per patient per week. Equally important, considering the specialised nature of the treatment, clinicians are expected to invest time to complete training which requires them to attend two comprehensive training courses and complete 90 items of assigned self-study homework to render them specialised in DBT treatment (Choi-Kain, Albert & Gunderson, 2016). Moreover, since DBT predicts the possibility of clinician burnout (mental and physical exhaustion from prolonged involvement in emotionally demanding work situations), it includes additional resources for frequent supervision and consultation group meetings as well (Carmel, Fruzzetti & Rose, 2013). Resources are always limited in a budget constrained healthcare system; hence, clinical priorities should take into consideration the graveness of the disorder, the expected benefits of the treatment and analyse the cost-effectiveness between the two.
DBT has the potential to be more cost-effective by adapting and shortening the standard treatment, which ultimately cuts the cost of treatment. Explicitly, the multicomponent nature of DBT should be systematically examined and dismantled to identify which components are sufficient to produce a less intensive but still highly effective treatment. Linehan, et al. (2015) conducted an experiment to evaluate which DBT components are actually necessary to achieve positive outcomes. In particular, she investigated the importance of the skills training component of DBT by comparing three treatment conditions: (1) DBT skills training (DBT-S) that occurs without individual therapy and replaces that with case management; (2) DBT individual therapy (DBT-I) that occurs without without DBT skills training and replaces that with an activity-based support group, and (3) standard DBT which is equipped with all the components of DBT including skills training group and individual therapy. Surprisingly, all three conditions resulted in significantly reduced suicide attempts, suicide ideation, lethality and use of crisis services. Specifically, the DBT-S condition showed greater reduction in frequency of self-harm than the DBT-I condition. Surprisingly, standard DBT did not show a significant difference in effectiveness compared to DBT-S despite the substantial gap in total hours of treatment (average 55.3 hours in standard DBT versus 31.7 hours in DBT-S) (Linehan, et al., 2015). Overall the findings suggest that skills training is a necessary component to achieve optimal outcomes in suicidality and illustrates that well-organised but less intensive DBT treatments are also effective. Moreover, they challenge previous claims that DBT must be employed in its methodological standard format to prove effective.
On a separate note, Haga and colleagues (2018) recently published a distinct dismantling study assessing the cost-effectiveness of DBT for adolescents (DBT-A) by comparing it to enhanced usual care (EUC). The research described DBT-A as a shortened version of DBT that has been adapted for adolescents to focus more on teaching distress tolerance skills and enhancing family functioning. This treatment was delivered in an outpatient setting with the aim of using more outpatient resources than usual care and, consequently, reduce the need for hospitalisation. While DBT-A was superior to EUC in reducing self-harm over the set time interval, the study found no statistical significant differences in total treatment cost between DBT-A and EUC, however, that could be due to low statistical power of their small sample size (Haga, et al., 2018). To elaborate, DBT-A group may have had a higher outpatient treatment cost during the intervention but the EUC groups had a higher cost during the follow-up period, which shows that intensified use of resources during the intervention resulted in a reduced need for treatment during follow-up sessions. Additionally, DBT-A patients rapidly improved at 19 weeks, considering the total treatment cost to be similar at 71 weeks, this shows that initial extra use of resources garnered a higher improvement and gave a better value for money. Generally speaking, the present study provided findings that lend support for DBT-A having a higher probability of being more cost-effective than EUC, as it improved self-harm at a faster rate and similar cost, and hence, may be a better option for adolescents. Future studies should expand on the study by increasing the sample size in order to properly evaluate the cost-effectiveness of DBT-A.
CONCLUSION
Based on a critical evaluation of the evidence, I conclude that DBT is a promising approach that is empirically-supported to be effective in its goals to reduce suicidality in BPD patients. DBT has challenged the notion of BPD individuals rejecting therapeutic interventions (Allen, 1997) and has shown to be one of the best evidence-supported treatment for a disorder that used to be perceived as “untreatable” (Fassbinder, 2017, p. 2). This essay revealed a correlation between the personality characteristic of impulsivity and suicide risk in BPD patients, and proposed that reducing impulsivity may be the basis of DBT’s success in lowering suicidal behaviour. In particular, DBT’s mindfulness module in skill training demonstrated to be a salient component of crisis intervention, and researchers should aim to further enhance this module to promote higher efficiency when working with suicidal patients. Nonetheless, even with adapting and shortening the treatment, DBT still incurs high patterns of service utilization and therefore high expenditure for its patients. The preliminary efficiency research mentioned above (Haga, et al., 2018) suggested that the treatment has the potential to be cost-effective for individuals with parasuicidal behaviour. Subsequently, more cost-effectiveness studies need to be conducted to systematically measure the input (treatment cost) and output (health improvement) in order for DBT to gain traction and be sustained in healthcare settings. Current strategies should also focus on the neurobiological underpinnings of BPD, to further understand and manage this high-risk disorder, and advance the development and dissemination of a more cost-effective DBT intervention.
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