Approximately 30% of those with borderline personality disorder (BPD) meet post-traumatic stress disorder (PTSD) diagnostic criteria, and approximately 25% of those with PTSD meet BPD diagnostic criteria (Pagura et al., 2010; Pietrzak et al., 2011). When comorbid, the presentation includes greater symptom severity and healthcare burden (Jowett et al., 2019; Pagura et al., 2010; Scheiderer et al., 2015; Barnicot & Crawford, 2018).
As such, BPD-PTSD is common yet difficult to treat (Harned et al., 2010). Whilst treatment guidelines exist for each disorder, minimal treatment guidance exists for this comorbidity, and there is limited literature regarding the efficacy and safety of BPD-PTSD treatments. Thus, Zeifman et al. (2021) conducted a systematic review of various treatment outcomes of BPD-PTSD.
A systematic review was conducted, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Moher et al, 2009). The following databases were searched: PsycInfo, MEDLINE, and PubMed. The methodology of studies was quality assessed by authors using the Downs and Black Checklist (Downs & Black, 1998).
The authors included studies with participants under 18 years old who have a diagnosis of BPD, PTSD, or BPD-PTSD including subclinical samples involved in psychotherapeutic treatment with treatment outcomes assessed via a valid measure. Specific types of publications (e.g., reviews, case studies, and conference abstracts) were excluded.
21 articles were included in this systematic review.
Impact of PTSD on BPD outcomes
Barnicot and Crawford (2018) found that participants with BPD receiving mentalisation-based therapy or dialectical behavioural therapy (DBT) had a positive association between PTSD severity and self-harm frequency post-treatment. However, PTSD was not associated with increased BPD frequency, severity, or self-harm likelihood post-treatment.
Numerous studies have found that PTSD symptoms significantly reduced after various treatments such as trauma-focused treatments and DBT, for those with BPD-PTSD, suggesting positive PTSD outcomes. For example, one randomised controlled trial (RCT) comparing trauma-focused treatment with community treatment by experts (including DBT elements) for BPD-PTSD, found significant PTSD symptom reduction, with no significant differences between groups (Pabst et al., 2014). Another RCT found that DBT plus DBT prolonged exposure (DBT-PE) had greater outcomes in those with BPD-PTSD compared to DBT alone (Harned et al., 2014).
Trauma-focused treatment for PTSD
Impact of BPD on PTSD symptoms
Treatments such as outpatient Eye Movement Desensitization and Reprocessing (EMDR) (Slotema et al., 2019), residential trauma-focused PTSD treatment (Bohus et al., 2013), and PE and Cognitive Processing Therapy (CPT; Clarke et al., 2008; Feeny et al., 2002; Holder et al., 2017), found no effect of BPD-PTSD or subclinical BPD-PTSD, on trauma-focused treatment outcomes. However, De Jongh et al. (2020) found significant reductions in clinician-assessed PTSD symptoms after brief intensive trauma-focused treatment, including EMDR and PE, in those with BPD. Lastly, Feeny et al. (2002) found those without BPD characteristics, compared to those with, were more likely to achieve adequate end-state functioning following trauma-focused treatment.
Numerous studies have found that BPD symptoms significantly reduced after various treatments such as trauma-focused treatments and Narrative Exposure Therapy (NET), for those with BPD-PTSD, suggesting positive BPD outcomes (Pabst et al., 2014; Steuwe et al., 2016, De Jongh et al., 2020).
Non-trauma-focused treatment for PTSD
Process-oriented group therapy for PTSD
Process-oriented group therapy does not appear promising for PTSD, with Cloitre and Koenen’s (2001) uncontrolled trial finding that those with PTSD and BPD-PTSD did not show significant PTSD symptom decreases post-treatment.
Cognitive behavioural therapy for PTSD (non-trauma-focused)
Studies suggest that Cognitive Behavioural Therapy (CBT) for PTSD leads to positive clinical outcomes for PTSD, but not for BPD (i.e., Kredlow et al., 2017).
Stage-based treatment for BPD-PTSD
In stage-based treatment, trauma-focused treatment occurs after safety concerns have eased (e.g., suicide attempts have ceased) and individuals demonstrate skills to tolerate or regulate distressing emotions.
Dialectical behaviour therapy plus dialectical behaviour therapy prolonged exposure
DBT plus DBT-PE seems to be a promising treatment for those with BPD-PTSD, including those who have self-harm and suicidal urges. In an uncontrolled study, Harned et al. (2012) found that those with BPD-PTSD presented with suicidal behaviour or serious non-suicidal self-injury (NSSI) and/or imminent threat of suicidal behaviour within the last three months who received one year of DBT plus DBT-PE no longer met PTSD criteria. Additionally, suicidal ideation significantly decreased, and there were no significant differences in self-harm or suicidal urges before or after trauma-focused sessions.
Similarly, an RCT by Harned et al. (2014) found that, compared to DBT, DBT plus DBT-PE was associated with significant PTSD symptom reduction. Post-treatment, between-group effect sizes were moderate regarding decreased attempted suicide and small-to-moderate for PTSD symptoms. Moreover, DBT plus DBT-PE, compared to DBT alone, was associated with decreased completed suicide, attempted suicide, NSSI, and PTSD symptoms, remaining at a three-month follow-up.
Dialectical behaviour therapy for PTSD
DBT-PTSD seems to be a promising treatment for those with BPD-PTSD with the majority of research suggesting positive clinical outcomes, although some suggest greater promises for PTSD compared to BPD (Steil et al., 2018; Bohus et al., 2013).
Eye movement desensitisation and reprocessing plus stabilisation-based sessions
Slotema et al. (2019) investigated EMDR plus stabilisation-based sessions for those with BPD-PTSD receiving TAU in an outpatient setting, finding significant pre-to-post decreases in PTSD symptoms, but not NSSI.
Stage-based treatments have a growing evidence base, suggesting they are effective and safe for PTSD treatment, and perhaps also for BPD. BPD-specific treatments alone are likely inadequate to treat BPD-PTSD with a focus on decreasing PTSD symptoms. Findings also suggest that trauma-focused treatments do not lead to an increased risk of self-harm or suicide and may even be effective in targeting such risks in those with BPD-PTSD.
Strengths and limitations
The authors included various types of studies making the review well-rounded whilst being considered good quality regarding both uncontrolled and controlled trials. The authors also included a healthy amount of RCTs which are a gold standard in research, cultivating rich evidence with minimal bias (Hariton & Locascio, 2018). Moreover, they did not use their own previous studies to minimise conflicts of interest and reduce the likelihood of researcher bias. Multiple databases were searched, and this consequently yields more research papers which increases the thoroughness and validity of the review (Zhao, 2014).
Many of the studies included were small treatment trials, and this can be considered a limitation due to the risk of reduced reliability, making it difficult to make strong conclusions (Hackshaw, 2008). Additionally, many participants in the included studies did not meet a full diagnosis of PTSD or BPD, thus subclinical populations may have affected the interpretation of the findings. As such, it could be that subclinical populations affected the results of some studies, as results may have differed if participants were only those who met diagnostic criteria. The majority of the eligible studies lacked real-world examination. In fact, only one study had a real-world examination with promising findings (see Harned et al., 2020); However, clinical improvement decreased when compared to previous trials, suggesting that the research may not translate well to real-world settings, thus limiting generalisability to the real world. Moreover, the authors did not consider the cost-effectiveness, availability, or accessibility of BPD-PTSD treatments, which may limit the use of these treatments. For example, adding a trauma-focused component likely leads to an additional accessibility barrier due to increased specialised training and clinician time, however, this was not considered.
Implications for practice
By exploring the underlying mechanisms that lead to improved clinical outcomes, clinicians can better understand which treatment components to prioritise in their practice. It is believed that changes in BPD-PTSD symptoms occur mostly during and after trauma-focused components of stage-based treatments. Thus, this challenges the current idea that trauma-focused components should be offered post-stabilisation. Future research could investigate offering trauma-focused components before or alongside BPD-specific treatments, which may be most feasible in ‘safer’ settings such as residential homes, or alongside brief suicide prevention interventions. Evidence-driven implementation of this intervention may improve service users’ trajectory as a means of preventing a longer duration of symptoms. This is particularly important in BPD-PTSD, as although there is growing literature regarding mechanisms of change in BPD, this remains limited regarding BPD-PTSD. Furthermore, our understanding of patient characteristics determining those who would best benefit from BPD-PTSD treatments is still limited. Consequently, future exploration of moderators of treatment outcomes is needed to lead treatment selection in mental health settings.
Future qualitative research can develop our understanding of service users’ experiences with these treatments, what they like/dislike, etc. Knowing this may also give us a better understanding of things such as drop-outs which can impact the effectiveness of treatments.
Statement of interests
Zeifman, R. J., Landy, M. S., Liebman, R. E., Fitzpatrick, S., & Monson, C. M. (2021). Optimizing treatment for comorbid borderline personality disorder and posttraumatic stress disorder: A systematic review of psychotherapeutic approaches and treatment efficacy. Clinical psychology review, 86, 102030. https://doi.org/10.1016/j.cpr.2021.102030
Barnicot, K., & Crawford, M. (2018). Posttraumatic stress disorder in patients with borderline personality disorder: Treatment outcomes and mediators. Journal of Traumatic Stress, 31, 899-908. https://doi.org/10.1002/jts.22340
Bohus, M., Dyer, A. S., Priebe, K., Krüger, A., Kleindienst, N., Schmahl, C., … & Steil, R. (2013). Dialectical behaviour therapy for post-traumatic stress disorder after childhood sexual abuse in patients with and without borderline personality disorder: A randomised controlled trial. Psychotherapy and Psychosomatics, 82, 221-233. https://doi.org/10.1159/000348451
Bohus, M., Kleindienst, N., Hahn, C., Müller-Engelmann, M., Ludäscher, P., Steil, R., … & Schmahl, C. (2020). Dialectical behavior therapy for posttraumatic stress disorder (DBTPTSD) compared with cognitive processing therapy (CPT) in complex presentations of PTSD in women survivors of childhood abuse: A randomized clinical trial. JAMA Psychiatry, 77, 1235-1245. https://doi.org/10.1001/jamapsychiatry.2020.2148
Clarke, S. B., Rizvi, S. L., & Resick, P. A. (2008). Borderline personality characteristics and treatment outcome in cognitive-behavioral treatments for PTSD in female rape victims. Behavior Therapy, 39, 72-78. https://doi.org/10.1016/j.beth.2007.05.002
Cloitre, M., & Koenen, K. C. (2001). The impact of borderline personality disorder on process group outcome among women with posttraumatic stress disorder related to childhood abuse. International Journal of Group Psychotherapy, 51, 379-398. https://doi.org/10.1521/ijgp.51.3.379.49886
De Jongh, A., Groenland, G. N., Sanches, S., Bongaerts, H., Voorendonk, E. M., & Van Minnen, A. (2020) The impact of brief intensive trauma-focused treatment for PTSD on symptoms of borderline personality disorder. European Journal of Psychotraumatology, 11, 1721142. https://doi.org/10.1080/20008198.2020.1721142
Downs, S. H., & Black, N. (1998). The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions. Journal of Epidemiology & Community Health, 52(6), 377-384. http://dx.doi.org/10.1136/jech.52.6.377
Feeny, N. C., Zoellner, L. A., & Foa, E. B. (2002). Treatment outcome for chronic PTSD among female assault victims with borderline personality characteristics: A preliminary examination. Journal of Personality Disorders, 16, 30-40. https://doi.org/10.1521/pedi.126.96.36.19955
Hackshaw, A. (2008). Small studies: strengths and limitations. European Respiratory Journal, 32(5), 1141-1143. https://doi.org/10.1183/09031936.00136408
Hariton, E., & Locascio, J. J. (2018). Randomised controlled trials—the gold standard for effectiveness research. BJOG: an international journal of obstetrics and gynaecology, 125(13), 1716. https://doi.org/10.1111/1471-0528.15199
Harned, M. S., Korslund, K. E., & Linehan, M. M. (2014). A pilot randomized controlled trial of dialectical behavior therapy with and without the dialectical behavior therapy prolonged exposure protocol for suicidal and self-injuring women with borderline personality disorder and PTSD. Behaviour Research and Therapy, 55, 7-17. https://doi.org/10.1016/j.brat.2014.01.008
Harned, M. S., Korslund, K. E., Foa, E. B., & Linehan, M. M. (2012). Treating PTSD in suicidal and self-injuring women with borderline personality disorder: Development and preliminary evaluation of a dialectical behavior therapy prolonged exposure protocol. Behaviour Research and Therapy, 50, 381-386. https://doi.org/10.1016/j.brat.2012.02.011
Harned, M. S., Rizvi, S. L., & Linehan, M. M. (2010). Impact of co-occurring posttraumatic stress disorder on suicidal women with borderline personality disorder. American Journal of Psychiatry, 167, 1210-1217. https://doi.org/10.1176/appi.ajp.2010.09081213
Holder, N., Holliday, R., Pai, A., & Surís, A. (2017). Role of borderline personality disorder in the treatment of military sexual trauma-related posttraumatic stress disorder with cognitive processing therapy. Behavioral Medicine, 43, 184-190. https://doi.org/10.1080/08964289.2016.1276430
Jowett, S., Karatzias, T., & Albert, I. (2019). Multiple and interpersonal trauma are risk factors for both post‐traumatic stress disorder and borderline personality disorder: A systematic review on the traumatic backgrounds and clinical characteristics of comorbid post‐ traumatic stress disorder/borderline personality disorder groups versus single‐disorder groups. Psychology and Psychotherapy: Theory, Research and Practice, 93, 621-638. https://doi.org/10.1111/papt.12248
Kredlow, M. A., Szuhany, K. L., Lo, S., Xie, H., Gottlieb, J. D., Rosenberg, S. D., & Mueser, K. T. (2017). Cognitive behavioral therapy for posttraumatic stress disorder in individuals with severe mental illness and borderline personality disorder. Psychiatry Research, 249, 86-93. https://doi.org/10.1016/j.psychres.2016.12.045
Masland, S. R., Cummings, M. H., Null, K. E., Woynowskie, K. M., & Choi-Kain, L. W. (2019). Changes in post-traumatic stress disorder symptoms during residential treatment for borderline personality disorder: A longitudinal cross-lagged study. Borderline Personality Disorder and Emotion Dysregulation, 6, 15. https://doi.org/10.1186/s40479-019-0113-4
Moher, D., Liberati, A., Tetzlaff, J., Altman, D. G., & Prisma Group. (2009). Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med, 6, e1000097. https://doi.org/10.7326/0003-4819-151-4-200908180-00135
Pabst, A., Schauer, M., Bernhardt, K., Ruf-Leuschner, M., Goder, R., Elbert, T., … & SeeckHirschner, M. (2014). Evaluation of narrative exposure therapy (NET) for borderline personality disorder with comorbid posttraumatic stress disorder. Clinical Neuropsychiatry, 11, 108-117. Retrieved from: http://nbn-resolving.de/urn:nbn:de:bsz:352-0-279326
Pagura, J., Stein, M. B., Bolton, J. M., Cox, B. J., Grant, B., & Sareen, J. (2010). Comorbidity of borderline personality disorder and posttraumatic stress disorder in the US population. Journal of Psychiatric Research, 44, 1190-1198.https://doi.org/10.1016/j.jpsychires.2010.04.016
Pietrzak, R. H., Goldstein, R. B., Southwick, S. M., & Grant, B. F. (2011). Personality disorders associated with full and partial posttraumatic stress disorder in the US population: Results from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. Journal of Psychiatric Research, 45, 678-686. https://doi.org/10.1016/j.jpsychires.2010.09.013
Scheiderer, E. M., Wood, P. K., & Trull, T. J. (2015). The comorbidity of borderline personality disorder and posttraumatic stress disorder: Revisiting the prevalence and associations in a general population sample. Borderline Personality Disorder and Emotion Dysregulation, 2, 11. https://doi.org/10.1186/s40479-015-0032-y
Slotema, C. W., van den Berg, D. P., Driessen, A., Wilhelmus, B., & Franken, I. H. (2019). Feasibility of EMDR for posttraumatic stress disorder in patients with personality disorders: A pilot study. European Journal of Psychotraumatology, 10, 1614822. https://doi.org/10.1080/20008198.2019.1614822
Steil, R., Dittmann, C., Müller-Engelmann, M., Dyer, A., Maasch, A. M., & Priebe, K. (2018). Dialectical behaviour therapy for posttraumatic stress disorder related to childhood sexual abuse: A pilot study in an outpatient treatment setting. European Journal of Psychotraumatology, 9, 1423832. https://doi.org/10.1080/20008198.2018.1423832
Steuwe, C., Rullkötter, N., Ertl, V., Berg, M., Neuner, F., Beblo, T., & Driessen, M. (2016). Effectiveness and feasibility of narrative exposure therapy (NET) in patients with borderline personality disorder and posttraumatic stress disorder – a pilot study. BMC Psychiatry, 16, 254. https://doi.org/10.1186/s12888-016-0969-4
Zhao, J. G. (2014). Combination of multiple databases is necessary for a valid systematic review. International orthopaedics, 38(12), 2639-2639. https://doi.org/10.1007/s00264-014-2556-y