Re-examining the comorbidity between borderline personality disorder and post-traumatic stress disorder: a systematic narrative review

Abstract

Background

Borderline personality disorder (BPD) and post-traumatic stress disorder (PTSD) frequently co-occur, yet research on this comorbidity is limited. Recent advancements in this area have led to the emergence of new studies that provide insight into the relationship between these disorders, potential treatment interventions, and the ongoing debate surrounding the diagnosis of Complex PTSD. This review aims to examine these findings and evaluate whether they address key gaps identified in the review by Frías & Palma (Psychopathology 48(1):1–10, 2014).

Methods

A literature search was conducted using Medline and PsycINFO databases covering the period from 2014 and 2024, using the following descriptors: ‘post-traumatic stress disorder’, ‘posttraumatic stress disorder’, ‘PTSD’, ‘borderline personality disorder’, and ‘BPD’.

Results

A total of 27 studies met the inclusion criteria for examining this comorbidity, with the majority focusing on psychotherapy treatments. Consistent with previous findings, high comorbidity rates persist in clinical and community samples, and emotion dysregulation appears to be a core feature of BPD-PTSD. Contrary to common belief, a comorbid diagnosis of PTSD did not hinder treatment effectiveness, and individuals with a dual diagnosis showed improvements comparable to those with either disorder alone. Although some patients report increased distress or dysfunction, BPD-specific, trauma-focused, and integrated treatments are well-accepted in BPD-PTSD populations. While BPD-specific interventions are beneficial in managing BPD symptoms, evidence suggests that trauma-focused treatments are the most validated and central approaches for addressing this comorbidity. Incorporating emotion regulation techniques as strategies within or alongside trauma-focused treatments may further enhance outcomes for individuals with BPD-PTSD.

Conclusions

Our review builds on evidence that this comorbidity is treatment responsive. Despite the expanding understanding of these co-occurring disorders, gaps in the literature prevail. Further research on the prevalence, course, and etiology is needed, as well as on the efficacy of psychopharmacology treatments and the underrepresentation of men in BPD-PTSD samples.

Introduction

Borderline personality disorder is a condition characterized by a pervasive pattern of instability in interpersonal relationships, self-image, and affect, marked by impulsivity and a fear of abandonment [1]. BPD affects approximately 1–2% of the general population and is associated with high rates of self-harm, suicide, and psychiatric comorbidity [2]. Post-traumatic stress disorder, on the other hand, is characterized by intrusive memories, avoidance behaviours, negative alterations in cognition and mood, and heightened arousal following exposure to trauma. PTSD alone is associated with significant functional impairment, emotional dysregulation, and reduced quality of life [1]. Given the well-established relationship between BPD and trauma, comorbid BPD-PTSD has garnered attention due to its heightened prevalence, implications for patient well-being, and the challenges it presents both conceptually and in treatment. While a substantial body of research has examined each disorder independently, comparatively little work has explored their co-occurrence.

Frias and Palma [3] reported that individuals with comorbid BPD-PTSD experience greater clinical and functional impairment and higher emotional dysregulation compared to those with BPD alone. They also found preliminary evidence that psychotherapy can be effective in addressing this comorbidity. Additionally, they highlighted several gaps in the literature, including a lack of studies on men with BPD, limited direct comparisons between BPD and CPTSD, and a need for longitudinal and controlled trials assessing the efficacy of psychotherapy and psychopharmacological treatments.

Since their review, research has expanded in several areas over the last decade. Given these developments, the present review synthesizes recent evidence on the prevalence, etiology, and treatment outcomes of adults with BPD and comorbid PTSD. It also outlines treatments developed to address this comorbidity and highlights the increasing focus on distinguishing complex PTSD from BPD-PTSD.

Methods

A literature review was conducted via Ovid Medline and PsycINFO from September 2013 to July 2024 using the following keywords: ‘post-traumatic stress disorder’, ‘posttraumatic stress disorder’, ‘PTSD’, ‘borderline personality disorder’, and ‘BPD’. The search was limited to English language articles which were selected based on their provision of evidence and/or insight into comorbid PTSD in adults with BPD. Primary studies, reviews, and meta-analyses addressing the prevalence of co-occurrence, potential etiological mechanisms, and implications for course and treatment were included.

Exclusion criteria consisted of studies that did not focus on adults with clinically diagnosed BPD-PTSD using valid diagnostic processes such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) or the International Classification of Diseases (ICE). Case studies, protocols, questionnaire development studies, and grey literature were excluded. Given this review’s focus on the clinical features of this comorbidity, psychological and neuropsychological experiments (e.g., neuroimaging, stimulus-response, and biological studies) were also excluded.

Study selection was facilitated using Covidence, with two independent reviewers screening each record and resolving any conflicts through discussion. Data extraction followed a standardized table structured around key study characteristics including ‘author’, ‘year’, ‘study design’, ‘sample size’, ‘population characteristics’, ‘treatment’, ‘outcomes measured’, and ‘main findings’. Most included studies focused on treatment, so data collection emphasized treatment-related outcomes. Specifically, we sought data on symptom improvement for both BPD and PTSD, including measures of symptom reduction following interventions. For each outcome domain, all available results were extracted when possible, including multiple time points and measurement scales. When data were missing or unclear, no assumptions were made, and these instances were noted. A second reviewer independently completed data extraction on a sub-sample of the papers (n = 8), confirming the accuracy of the data extraction (Table 1).

Table 1.

Characteristics of Included Publications

ID	First Author	Year	Study Design	Sample Size	Population Characteristics	Treatment	Outcomes Measured	Main Findings
11	Atkinson	2024	Review	N/A	Participants with BPD compared to those with CPTSD and PTSD	N/A	N/A	Despite overlapping symptomology, the majority of studies identified distinct profiles for CPTSD and BPD and supported the distinction between the diagnostic constructs. CPTSD and BPD can present comorbidly, and these individuals are more likely to have experienced earlier, multiple and interpersonal forms of trauma, resulting in greater functional impairment, dissociation, and lower levels of life satisfaction.
8	Barnicot	2018	Observational	90 (n = 67 comorbid)	BPD patients from PD services across the UK	DBT or MBT	BPD and PTSD symptoms, self-harm, emotion dysregulation (ED), and dissociation	A comorbid PTSD diagnosis does not inherently lead to poorer treatment outcomes in patients with BPD. However, more severe PTSD or unresolved PTSD symptoms are associated with poorer outcomes due to their impact on emotional dysregulation. Addressing PTSD symptoms, particularly through interventions targeting emotion regulation, may optimize treatment outcomes.
2	Boritz	2016	Secondary Analysis	180	BPD-PTSD and history of at least 2 suicide attempts or non-suicidal self-injury (NSSI) episode in past 3 months	DBT vs. GPM	BPD severity, NSSI, and global psychological distress	BPD-PTSD patients report higher global psychological distress at baseline and end of treatment. Both groups showed similar improvements in suicide attempts, NSSI, global psychological distress, and BPD symptoms over treatment and at follow-up. However, patients with comorbid PTSD may require longer or trauma-focused treatment to fully address the global distress.
6	Cackowski	2016	Observational	367 (n = 142 comorbid)	Treatment seeking females with BPD with and without PTSD	N/A	ED, intrusions, dissociation, suicide attempts, NSSI, and child sexual abuse (CSA)	BPD patients with PTSD exhibited higher dissociation levels and more frequent suicide attempts; however, these associations became non-significant when controlling for CSA. PTSD was not linked to overall BPD severity but was associated with elevated intrusion and affect regulation difficulties.
13	Ford	2021	Review	N/A	N/A	N/A	Prevalence, phenomenology, role of trauma, neuropsychological basis, attachment, ED, and dissociation	PTSD, CPTSD, and BPD are distinct constructs. PTSD and CPTSD symptoms can occur without BPD, but BPD symptoms often appear alongside PTSD or CPTSD symptoms rather than alone. These disorders may exist on a continuum based on a progression from PTSD to CPTSD and ultimately comorbid BPD/CPTSD.
16	Gratz	2020	Observational	56 (n = 14 comorbid)	Female BPD patients with and without comorbid PTSD from an outpatient DBT clinic	DBT	BPD and PTSD symptoms, self-harm, and emotion regulation	The presence of a PTSD diagnosis was not associated with poorer treatment responses to DBT. Instead, it was linked to greater improvements in BPD symptom severity. Patients with PTSD did not report greater clinical severity at intake on most measures and experienced significant improvement in PTSD symptom severity, likely due to DBT’s focus on emotion regulation. Integrating emotion regulation (ER) skills training may enhance outcomes for these patients, though older individuals may require longer treatment with DBT.
27	Harned	2014	Pilot RCT	26	Treatment seeking females with BPD-PTSD and recent recurrent self-injury or at least one NSSI episode in past 8 weeks	DBT-PE vs. DBT	PTSD severity, self-harm, dissociation, trauma-related guilt cognitions, shame, general psychological well-being, depression, and anxiety	Both treatments were well-accepted, though most participants (73%) preferred the combined DBT PE approach over DBT alone. Patients in DBT PE experienced significantly greater reductions in PTSD severity and superior outcomes across a range of domains, with effects remaining more stable over time. They were also 1.3 times more likely to report significant improvements in PTSD (80% vs. 60%) and 2 times more likely to achieve diagnostic remission (80% vs. 40%). While DBT reduces PTSD severity, targeted treatment is likely necessary to reach the level of remission.
28	Harned	2016	Secondary Analysis	38	Female participants with BPD-PTSD and recent suicidal behaviour or serious NSSI in the past 2 or 3 months	DBT PE vs. DBT (and compares DBT-No DBT PE)	BPD and PTSD symptoms, dissociation, urge to engage in problem behaviours, and global well-being	PTSD symptoms did not improve until Stage 2, where DBT PE was introduced, leading to significant reductions in PTSD severity that continued throughout Stage 3. Additionally, BPD severity and state dissociation also declined in Stage 3, suggesting these improvements may depend on effective PTSD treatment. Patients in DBT PE reported significantly greater global well-being, indicating that adding DBT PE to DBT may enhance PTSD and comorbid symptom improvements.
18	Harned	2018	Secondary Analysis	26	Treatment seeking females with BPD-PTSD and recent recurrent self-injury or at least one NSSI episode in past 8 weeks	DBT PE vs. DBT	Global functioning, global social adjustment, interpersonal problems, quality of life, unhealthy days, PTSD severity, and post-traumatic cognitions	DBT PE significantly improved global social adjustment, health-related quality of life, and good global functioning compared to DBT alone, driven by greater reductions in PTSD severity and maladaptive post-traumatic cognitions. Reductions in PTSD severity improved global functioning, social adjustment, and quality of life, while changes in maladaptive cognitions specifically affected interpersonal problems and quality of life. However, DBT PE was not more effective than DBT in improving interpersonal functioning or quality of life, suggesting these may be more tied to BPD-related negative self-views. This aligns with research showing that PTSD avoidance and numbing symptoms particularly impair social and global functioning
9	Harned	2020	Secondary Analysis	26	Treatment seeking females with BPD-PTSD and recent recurrent self-injury or at least one NSSI episode in past 8 weeks	DBT PE vs. DBT	PTSD severity, posttraumatic cognitions, guilt, shame, ED, and experiential avoidance (EA)	Between-person differences in post-traumatic cognitions (PTCs), shame, ED, and EA, but not guilt, were associated with more severe PTSD and slower symptom improvement, suggesting that targeting these factors in DBT before DBT PE may enhance treatment gains. PTSD severity did not predict changes in shame, guilt, or EA, supporting their role in maintaining PTSD rather than vice versa. However, PTSD severity was linked to greater ED and PTCs, aligning with evidence that PTSD exacerbates ED and hinders improvement in self-injurious behaviour among individuals with BPD.
20	Hood	2024	Secondary Analysis	99 (n = 29 comorbid)	Treatment seeking individuals with BPD with and without PTSD	BPD Compass	BPD and PTSD symptom severity, BPD features, and personality dimensions	BPD Compass significantly reduced BPD features and aspects of neuroticism (e.g., anxious uncertainty, despondence, affective and behavioral dysregulation) compared to the waitlist condition (WLC), but not PTSD symptoms. Reductions in PTSD symptoms predicted later decreases in BPD features and personality traits, but not the reverse, suggesting PTSD improvement precedes BPD change. PTSD reductions were also linked to later declines in despondence, affective dysregulation, and dissociation, indicating these traits may both influence and reflect PTSD improvement. While BPD Compass appears effective for BPD and some personality dimensions, its impact on PTSD and dissociation needs further study.
14	Jowett	2020	Review	N/A	Individuals with comorbid BPD-PTSD, BPD-only, and PTSD-only	N/A	Trauma exposure, self-injury, interpersonal difficulties, ED, depression, anxiety, dissociation, and substance abuse	Individuals with comorbid BPD-PTSD experience greater exposure to multiple and interpersonal traumatic events and elevated emotion dysregulation compared to those with BPD or PTSD alone. Self-injury was primarily associated with BPD and was not elevated by comorbid PTSD. There was no significant elevation in substance use or depression in the comorbid group, while findings on interpersonal problems, dissociation, and anxiety were inconclusive.
7	Kleindienst	2021	Secondary Analysis	93	Females with a dual diagnosis of BPD with child abuse (CA)-related PTSD	DBT-PTSD vs. CPT	BPD and PTSD severity, maladaptive behaviours (NSSI/suicide attempts), dissociation, depressive symptoms, and global functioning	Severity of BPD and PTSD symptoms decreased across both treatment groups, though differential effects were significantly in favour of DBT-PTSD (60% vs. 28%). The DBT-PTSD group also showed greater improvement in maladaptive behaviours and intensity/duration of dissociative symptoms, an important barrier to treatment success. Thus, the addition of trauma-focused elements seems to be beneficial for this population. However, DBT-PTSD may be a more effective treatment.
30	Kolthof	2022	Non-randomized controlled trial	45	Patients with BPD-PTSD in inpatient setting	EDMR + PE	BPD and PTSD severity	BPD and PTSD symptoms decreased significantly after treatment, at 6-month follow-up, and one-year post-treatment, with 70% no longer meeting criteria for PTSD after 12 months and 73% no longer fulfilling diagnostic criteria for BPD. This suggests that short-term intensive trauma-focused treatment (without any form of emotion regulation or relaxation prior to treatment) is effective in treating comorbid symptoms and is a viable option for individuals with symptoms of BPD.
21	Kredlow	2017	Secondary Analysis	27 (Study 1) 55 (Study 2)	Individuals in community health centers with BPD-PTSD	CBT vs. treatment as usual (TAU) CBT vs. 3-session CBT	PTSD symptoms, feasibility/tolerability of CBT, depression, quality of life, and global functioning	CBT led to significant reductions in PTSD symptoms compared to TAU (Study 1) and the brief 3-session intervention (Study 2). The cognitive restructuring component of CBT further contributed to additional PTSD symptom reductions. Additionally, in the comorbid BPD sample, CBT had a broader impact, leading to a decrease in other symptoms, including depression. This is promising, given the high comorbidity rate between PTSD, BPD, and MDD. Individuals with BPD-PTSD can benefit from non-staged, trauma-focused CBT for PTSD.
29	Meyers	2017	Observational	33 (n = 16 comorbid)	Veterans enrolled in VA care with PTSD and a prior incomplete attempt at trauma-focused therapy due to BPD symptoms	DBT PE intensive outpatient program (IOP)	BPD and PTSD severity, strategies for coping with stressful life events (ER, mindfulness, crisis survival, reality acceptance, interpersonal effectiveness), and suicide ideation	DBT PE IOP can be safely and effectively implemented in a VA setting, with veterans reporting significant reductions in PTSD symptoms and improvements in positive coping across all outcome variables. There were no increases in self-harm, suicide attempts, hospitalizations, or dissociation. While all veterans accepted into the program had previously been unable to participate or complete trauma-focused treatment (TFT), the majority successfully completed the full treatment protocol and experienced clinically meaningful benefits, challenging the hesitancy to treat veterans with these comorbidities.
19	Pabst	2014	RCT	22	Females with BPD-PTSD in both inpatient and outpatient settings	NET vs. treatment by experts for BPD (TBE)	BPD and PTSD symptom severity, depressive symptoms, and dissociation	Clinicians who received 2-day training in NET achieved notable improvements in patients with BPD-PTSD across all outcomes. TBE also reduces these symptoms but requires more intensive training in DBT and other techniques. While TBE teaches patients how to cope with symptoms, promoting control and self-regulation, NET targets the fear structure, reducing dissociative and PTSD-related symptoms. This may lead to a reduction in overlapping BPD symptoms, such as ED. Future studies should consider including NET within DBT-based treatment for these patients.
12	Paris	2023	Review	N/A	N/A	N/A	Childhood trauma, ED, the role of biology, and gene-environment interactions	Argues that a biopsychosocial theory is required to understand the development of BPD and opposes posttraumatic models, which consider trauma to be a primary risk factor while failing to account for interactions between life events, underlying trait profiles, and the role of resilience (i.e., differential susceptibility). If the diagnosis of BPD is to be renamed or replaced, CPTSD is too narrow a construct to capture its complexity fully and is inconsistent with models based on gene-environment interactions that drive the etiology of most mental disorders.
5	Scheiderer	2015	Observational	4104 (n = 547 comorbid)	Community sample from NESARC wave 2 with PTSD-only, BPD-only, or comorbid	N/A	Prevalence, CSA, health-related quality of life (HRQOL)	53.11% of those who met criteria for BPD also met criteria for lifetime PTSD; and 14.69% of those who met for PTSD also met for BPD. Individuals with a history of CSA had significantly greater odds (36%) of being in the comorbid group, suggesting it may be a precursor for this comorbidity. CSA may be even more of a predictor of BPD-PTSD comorbidity among men. Additionally, BPD-PTSD was linked to worse HRQOL and more intensive healthcare use compared to either disorder alone. Lifetime comorbidity of BPD and PTSD was associated with more dysfunction than either individual disorder
10	Scheiderer	2016	Observational	128	BPD outpatients with and without PTSD vs. a clinical control group of patients with major depressive disorder (MDD) or dysthymia (DYS)	Ecological momentary assessment (28-day collection period)	Affective instability	BPD-PTSD exhibited greater instability in sadness and fear compared to those with BPD alone, whereas individuals with MDD/DYS and PTSD showed lower instability in sadness and fear compared to those with MDD/DYS alone. There were no significant differences in the instability of overall negative affect, hostility, or positive affect across groups. The differences in instability were specific to sadness and fear, aligning with core emotional features of PTSD.
25	Slotema	2019	Open Pilot	47 (n = 22 comorbid)	Patients with BPD-PTSD or another PD from an outpatient PD treatment clinic (87% female)	EMDR + TAU	PTSD severity, dissociative symptoms, insomnia, NSSI, and auditory hallucinations	EDMR led to significant reductions in PTSD, dissociation, and insomnia severity, with no significant changes in hallucinations or NSSI. Following treatment, 40% of participants had PTSD severity scores below the threshold, indicating remission. There were no significant differences in outcomes between participants with BPD and those with other personality disorders.
23	Slotema	2020	Review + Meta Analysis	N/A	Male and female patients with BPD or BPD-PTSD	Psychotherapy interventions (PE, DBT, CBT, CPT, NET, and EMDR)	BPD and PTSD severity, depression, and anxiety	Psychotherapy was found to be superior to control conditions in RCTs, with a moderate effect size of 0.54 posttreatment, increasing to 0.82 at follow-up. In nonrandomized and uncontrolled studies, significant changes were observed across all outcomes, with moderate to large effect sizes. PTSD interventions were not associated with increases in self-injurious behaviour, suicide attempts, or hospitalizations.
22	Steuwe	2016	Non-randomized Pilot	11	Patients in a PD treatment center with BPD-PTSD and absence of intentional self-injury (91% female)	10-week NET and standard inpatient care (SIC)	Treatment feasibility, acceptability, and safety, BPD and PTSD severity, dissociation, depression, and quality of life	NET was a feasible, safe, and well-accepted treatment for individuals with SMI, with a 90% completion rate. It did not worsen symptom severity or increase self-harming behaviour at post-treatment or at 12-month follow-up. Completion of treatment led to significant improvements, including reductions in PTSD and BPD symptom severity, decreased depression and dissociation, and enhanced quality of life. These findings suggest that NET is as effective as other exposure-based PTSD treatments and is potentially effective in inpatient settings.
24	Steuwe	2021	RCT	58	Female BPD-PTSD patients in a residential treatment program	NET vs. DBT-bt	PTSD severity	Both NET and DBT-bt led to significant improvements in BPD and PTSD symptom severity, though NET showed significantly higher PTSD remission rates (33.3%) compared to DBT-bt (6.2%). PTSD remission was always accompanied by BPD remission, but not vice versa, highlighting the potential benefit of integrating trauma-focused practices into DBT. However, two patients in the NET group reliably worsened at 12-months follow-up compared to baseline, indicating greater variability in response to NET.
26	Wilhelmus	2023	Pilot Multiple Baseline	12	Participants with BPD-PTSD (83% female)	EDMR + TAU	PTSD severity, psychopathology, and the effect of psychopathology on life	EDMR led to a significant reduction in self-reported PTSD symptoms, and this effect was maintained after discontinuing treatment. Moreover, there was a reduction in general psychopathology, lessening its effects on daily activities and social functioning.
15	Williams	2017	Secondary Analysis	90 (n = 20 comorbid)	Veterans with PTSD with and without BPD (all female comorbid group)	N/A	PTSD and depressive symptoms, negative cognitions (NCs), and previous sexual trauma	Veterans with comorbid BPD and MST-PTSD exhibited higher levels of PTSD-related avoidance and depressive symptoms compared to veterans with PTSD alone. They also had greater trauma-related negative cognitions about both the world and the self. Notably, trauma NCs about the self were significant predictors of BPD.
17	Zeifman	2021	Review	N/A	N/A	BPD-specific treatments (DBT, MBT, and emotion regulation therapy), trauma-focused treatments (PE, CPT, NET, EMDR), and stage-based treatments (DBT, DBT PE, DBT-PTSD, and EMDR plus stabilization)	Treatment approaches, the impact of a comorbid diagnosis, treatment outcomes when only one disorder is targeted, the impact of stage-based approaches on both BPD and PTSD, and safety considerations	Studies on BPD-specific treatments indicate that PTSD does not hinder BPD-related improvements in comorbid individuals. However, these treatments alone may be insufficient for addressing PTSD symptoms. Findings on trauma-focused treatments suggest that BPD severity does not impede PTSD treatment outcomes. These treatments alone can lead to reductions in BPD symptoms. Stage-based treatments are safe and effective for PTSD and may also reduce BPD symptomology. Among them, DBT + DBT PE and DBT-PTSD have the strongest empirical support and may be more effective than BPD-specific or trauma-focused treatments alone. Regarding safety, studies indicate that trauma-focused treatments do not increase suicide or self-harm risk. Contrary to clinical concerns, they may be an effective way to address suicidality in individuals with BPD-PTSD.

Quality and risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Tools for the appropriate study design [4]. These processes were completed by the primary reviewer and verified by the secondary reviewer to ensure accuracy and completeness. Due to the variability in study designs, a narrative review approach was used instead of a meta-analysis.

For synthesis, studies were grouped under predetermined subheadings, established based on existing objectives and their clinical significance: prevalence, comorbidity patterns, etiological mechanisms, and treatment effectiveness. Within the treatment-focused studies, further distinctions were made according to treatment approach (e.g., trauma-focused, BPD-specific, or stage-based) to enable meaningful comparisons across interventions.

This review was initiated as part of a student thesis project and was not registered in any review registry. Clinical trial number: not applicable

Results

The search yielded 889 records, with 270 duplicates removed. After screening 619 titles and abstracts, 39 full-text articles were assessed for eligibility, of which 27 met the inclusion criteria and were included in the final review (see Fig. 1). The included studies consisted of observational designs (n = 7), secondary analyses (n = 8), pilot randomized controlled trials (RCTs; n = 2), full-scope RCTs (n = 2), an open pilot study (n = 1), a multiple baseline study (n = 1), reviews (n = 5), and a meta-analysis (n = 1). Sample sizes ranged from 11 to 547, with the majority of studies using BPD populations, with and without comorbid PTSD, and predominantly female samples (see Table 1).

Fig. 1.

PRISMA Diagram Literature Search Flow Chart

Of the 27 included studies, 1 focused on prevalence, 3 on comorbidity patterns, 4 on etiological mechanisms, and 19 on treatment effectiveness. Within treatment studies, 4 were BPD-specific, 5 were trauma-focused, and 8 were integrated treatments.

No data conversions, imputations, or statistical transformations were required; all extracted data were reported as presented in the original studies. In terms of quality assessment, most articles received high ratings, though there was variability across studies. Common issues in treatment studies included inadequate blinding and variability in the treatment delivered across study conditions. For reviews and meta-analyses, concerns included unaddressed confounds, lack of quality appraisal, and no mention of publication bias. No formal assessment of certainty in the body of evidence or risk of bias due to missing results (reporting biases) was conducted, given the narrative synthesis approach and limited statistical pooling (see Table 2).

Table 2.

Quality Assessment Ratings of Included Publications

ID	Author	Year	Study Design	JBI Tool Used	Quality Assessment	Limitations	Notes
1	Atkinson	2024	Review	Systematic Review	10/11 (high)	Acknowledges publication bias as a potential issue but does not formally assess
2	Barnicot	2018	Observational	Cohort Study	8/11 (high)	Does not state strategies to deal with confounding factors, some participants without PTSD outcomes at start of study, and limited analysis of attrition bias
3	Boritz	2016	Secondary analysis	RCT	10/13 (high)	Participants and those delivering treatment were not blind to treatment assignment. Unclear whether allocation was concealed
4	Cackowski	2016	Observational	Cross Sectional	7/8 (high)	Identifies CSA as confound but doesn’t state strategies to deal with it
5	Ford	2021	Review	Systematic Review	4/11 (low)	Doesn’t include information about methodology (search strategy, key words/databases), inclusion criteria, appraisal, or extraction
6	Frias	2015	Review	Systematic Review	7/11 (high)	No mention of appraisal, publication bias, or minimization of extraction errors
7	Gratz	2020	Observational	Cohort Study	9/11 (high)	Some participants without PTSD outcomes at start of study and limited analysis of attrition bias
8	Harned	2014	Pilot RCT	RCT	11/13 (high)	Participants were not blind to treatment and groups were not treated identically	Other three Harned studies use this 2014 RCT data
12	Hood	2024	Secondary analysis	RCT	9/13 (medium)	Participants and those delivering treatment were not blind to treatment assignment. Unclear whether allocation was concealed and limited analysis of attrition bias
13	Jowett	2020	Review	Systematic Review	11/11 (high)
14	Kleindienst	2021	Secondary analysis	RCT	12/13 (high)	Those delivering treatment were not blind to treatment assignment
15	Kolthof	2022	Non-randomized controlled trial	Quasi-experimental	6/9 (medium)	Lack of control group, incomplete follow-up, and limited analysis of attrition bias
16	Kredlow	2017	Secondary analysis	RCT	9/13 (medium)	Participants and those delivering treatment were not blind to treatment assignment. Unclear whether allocation was concealed and if ITT analysis was used.
18	Meyers	2017	Observational	Case Series	9/10 (high)	Unclear whether all eligible individuals during the study were enrolled.
19	Pabst	2014	Non-randomized controlled trial	Quasi-experimental	7/9 (high)	Lack of control group and groups were not treated identically
20	Paris	2023	Narrative review	Textual Evidence: Narrative	5/5 (high)
21	Scheiderer	2016	Observational	Case Control	8/10 (high)	Groups were not matched based on gender, whether they were receiving psychological treatment, or previous hospitalizations, relies on self-reported affect and compliance	Unclear on whether outcomes are assessed in a standard, valid, and reliable way if relying on self-report and compliance rates
22	Scheiderer	2015	Observational	Cross Sectional	7/8 (high)	Does not control for confounding variables (e.g., sociodemographic and comorbid diagnoses)
23	Slotema	2019	Open Pilot RCT	RCT	5/13 (low)	Open pilot study so no randomization or concealment. Treatment groups were not treated identically because TAU consisted of various different therapies for PDs, depending on individual needs and therapist training – EDMR was added to TAU for one group. Deviates from standard design
24	Slotema	2020	Review and meta-analysis	Systematic Review	11/11 (high)
25	Steuwe	2016	Non-randomized pilot	Case Series	10/10
26	Steuwe	2021	RCT	RCT	8/13 (medium)	Participants were randomly assigned but treatment allocation was not concealed from participants and therapists. Groups were not treated identically
27	Wilhelmus	2023	Pilot Multiple Baseline	Quasi-experimental	8/9 (high)	Follow-up was incomplete and not adequately analyzed across groups
28	Williams	2017	Secondary analysis	RCT	11/13 (high)	Allocation was not concealed and those delivering treatment were not blind
29	Zeifman	2021	Review	Systematic Review	10/11 (high)	No mention of limiting publication bias

Prevalence

The comorbidity rates of the included clinical samples ranged from 22.2% to 74.4%. Scheiderer et al. [5] was the only study to examine the prevalence of BPD-PTSD in a community sample using data from the National Epidemiological Survey on Alcohol and Related Conditions. They found that 3,074 individuals met criteria for PTSD, reflecting a prevalence rate of 8.87% in the general adult population. However, among individuals diagnosed with BPD, this rate increased to 53.11%, indicating that over half of those with BPD also met criteria for lifetime PTSD. In contrast, only 14.69% of individuals with PTSD also met criteria for BPD.

Symptom overlap

Comorbid BPD-PTSD is commonly associated with higher baseline clinical severity across numerous outcomes. Patients with this comorbidity may experience greater global psychological distress [6], intrusive symptoms, and overall dysfunction compared to those with either disorder alone [7]. They may also exhibit increased self-harming or high-risk behaviours, dissociation, and more severe depressive symptoms [8]. A prominent aspect of this comorbidity is difficulty regulating emotions or emotional instability. Although both disorders are characterized by emotional dysregulation (ED), individuals in this subgroup tend to experience pronounced levels. This amplified effect is likely driven by the presence of comorbid PTSD, which appears to exacerbate ED, and in turn, contribute to the treatment challenges and more severe clinical outcomes often observed in these cases [9, 10]. Notably, a study employing an ecological momentary assessment (EMA) design found that individuals with BPD-PTSD demonstrated greater emotional instability, particularly in relation to sadness and fear, compared to those with BPD-only, mirroring the core emotional features of PTSD [11].

These patterns are also characteristic of the highly debated diagnosis of Complex PTSD, which, although not the primary focus of this review, has emerged as an important theme in the literature. Considering the shared symptoms among BPD, PTSD, and CPTSD, as well as their potential to co-occur, individuals with BPD-CPTSD often experience earlier, more frequent, and varied forms of trauma, which can be associated with greater functional impairment, dissociation, and reduced life satisfaction [12]. While this review did not specifically examine BPD-CPTSD comorbidity, additional research has investigated their diagnostic distinctiveness as indicated in the discussion. As a result, CPTSD may not fully capture the complexity of BPD [13], and these disorders may alternatively be conceptualized along a continuum reflecting progression from PTSD to CPTSD, and in some cases, BPD-CPTSD comorbidity [14].

Etiology

In some research, both BPD and PTSD have been linked to trauma, although the mechanisms underlying their distinct clinical presentations remain unclear. A review comparing individuals with both BPD and PTSD to those with only one disorder found that, while interpersonal trauma serves as a risk factor for both disorders, people with BPD-PTSD experience multiple interpersonal traumatic events across childhood and adulthood. This heightened frequency, or poly-traumatization, may contribute to increased ED [15].

Specifically, child sexual abuse (CSA) has been recognized as a significant factor in the development of this comorbidity. Both studies by Scheiderer et al. [5, 11] examined the relationship between CSA and BPD-PTSD, identifying CSA as the most frequently reported traumatic experience in this subgroup (53%). They found that individuals with a history of CSA were 36% more likely to receive a comorbid diagnosis than either disorder alone. Interestingly, men who experienced CSA were three times more likely than women to have a comorbid diagnosis, suggesting that CSA may be an even stronger predictor of BPD-PTSD in males.

Similarly, Cackowski et al. [7] emphasized the prominence of CSA among patients with BPD, both with and without co-occurring PTSD. In their study, 76% of participants reported CSA as their primary trauma, with a higher prevalence in the comorbid BPD-PTSD group (81.2%) compared to the BPD-only group (53.1%). A significant positive correlation was also observed between CSA and the presence of BPD, highlighting CSA as a potential driving factor in the development of this comorbidity. Importantly, while individuals with BPD-PTSD reported increased rates of dissociation and suicide attempts, these associations became non-significant when controlling for CSA. This suggests that CSA itself, rather than PTSD alone, may be the primary factor influencing these outcomes.

The effects of sexual trauma also extend to veteran samples. Williams et al. [16] found that individuals with PTSD related to military sexual trauma (MST) and comorbid BPD reported higher levels of depression, PTSD-related avoidance, and trauma-related negative cognitions (NCs) compared to those with MST-related PTSD alone. These findings suggest that the presence of BPD may amplify depressive symptoms and negative beliefs about the self and the world. However, PTSD-related MST contributed to the development of negative cognitions, thereby increasing vulnerability to BPD and identifying MST as additional significant predictor of this comorbidity.

Treatment

In contrast to previous findings, having a comorbid PTSD diagnosis did not inherently lead to poorer treatment outcomes compared to BPD alone [6, 9, 17, 18]. However, more severe or unresolved PTSD was associated with negative outcomes or results, including heightened ED. As a result, recent studies emphasize the importance of primarily targeting PTSD symptoms and ED to subsequently reduce characteristics of BPD [9, 10, 19, 20].

BPD specific treatments

Barnicot and Crawford [9] examined whether comorbid PTSD impairs the effectiveness of evidence-based treatments for personality disorders (PDs), such as dialectical behavioural therapy (DBT) and mentalization-based therapy (MBT). The results showed that patients with and without comorbid PTSD benefitted equally from treatment, suggesting that PTSD does not compromise treatment effectiveness. While PTSD was not linked to more severe BPD symptoms at baseline, greater PTSD severity predicted more frequent self-harm and increased BPD severity at Month 12, independent of initial symptom severity or treatment type. This pattern suggests that these outcomes stem from unresolved PTSD symptoms rather than differences in initial functioning. Additionally, reductions in ED partially mediated improvements in PTSD symptoms, self-harm, and BPD severity at Month 12, accounting for 50% of the change in self-harm and 60% in BPD severity. This supports the role of ED as a key mechanism linking PTSD and self-injurious behaviour, suggesting that targeting ED through strategies embedded in DBT and MBT may be crucial for reducing PTSD symptoms and enhancing long-term outcomes.

Individuals with a comorbid diagnosis may also require extended treatment durations to achieve comparable outcomes. A secondary analysis of an RCT compared DBT to general psychiatric management among individuals with BPD, with and without PTSD. Both groups showed similar improvements in suicide attempts, non-suicidal self-injury (NSSI), global psychological distress, and BPD symptoms. However, those with comorbid PTSD reported significantly higher global distress at both baseline and post-treatment. These findings suggest that while comorbid PTSD does not impede positive treatment response, affected individuals may require additional treatment components to reach the same levels of psychological relief. This persistent distress may reflect unaddressed PTSD symptoms, raising the question of whether integrating trauma-focused elements is necessary to improve treatment outcomes [6].

This need for longer treatment may be particularly relevant for older individuals with BPD-PTSD. Gratz et al. [17] found that a comorbid PTSD diagnosis did not lead to poorer treatment outcomes; In fact, PTSD was associated with greater improvements in BPD symptom severity and a slight, though nonsignificant, reduction in PTSD symptoms. These results further support the efficacy of standard DBT for this population. Contrary to prior research, individuals with BPD-PTSD did not show greater baseline severity on most measures, except for PTSD symptoms. However, older patients in this group reported more severe ED, which was associated with significantly smaller improvements in both BPD symptoms and emotion regulation. This suggests that older patients may require additional treatment to achieve outcomes equivalent to those of younger patients.

BPD Compass, a new transdiagnostic psychotherapy that integrates cognitive, behavioural, and mindfulness-based skills to target personality dimensions, has been evaluated as a potential treatment for BPD-PTSD. In a secondary analysis of an RCT comparing BPD Compass to a waitlist control, Hood et al. [21] found that the treatment significantly reduced BPD features and aspects of neuroticism and agreeableness but did not significantly reduce PTSD severity. Nonetheless, participants who received BPD Compass showed greater improvement in PTSD symptoms than those in the waitlist condition. Reductions in PTSD symptoms preceded predicted decreases in BPD features and personality dimensions, whereas the reverse was not observed. These findings suggest that alleviating PTSD symptoms may drive subsequent improvements in BPD symptoms, challenging the conventional view that PTSD should only be addressed after BPD stabilization. Importantly, reductions in PTSD symptoms were also linked to lower levels of dissociation, underscoring the need for further research on dissociative processes within PTSD.

Trauma-focused treatments

A secondary analysis of two RCTs examined the feasibility and tolerability of trauma-focused cognitive behavioural therapy (CBT) for PTSD in individuals with severe mental illness (SMI), including schizophrenia-spectrum, bipolar, and severe mood or personality disorders, all receiving care in public mental health settings. In Study 1, 27 participants with BPD were included (15 received CBT, 12 received treatment as usual [TAU]), and in Study 2, 55 participants were included (29 standard-length CBT, 26 brief). TAU consisted of routine psychiatric care, case management, and pharmacotherapy. Participants had high baseline symptom severity, multiple comorbidities, and extensive trauma histories. While full-length CBT produced greater reductions in PTSD symptoms and diagnoses, even the brief 3-session version led to meaningful improvements, suggesting that individuals with BPD-PTSD may benefit from non-staged, trauma-focused CBT [22].

A pilot study by Steuwe et al. [23] evaluated narrative exposure therapy (NET) in an inpatient setting. The treatment was found to be safe and feasible, producing significant and sustained reductions in PTSD severity at both post-treatment and 12-month follow-up, along with decreases in depression and dissociation. BPD severity also improved at follow-up, with half of participants reporting benefits and none experiencing symptom worsening. These findings were later supported by a full-scale RCT, in which NET patients demonstrated significantly higher PTSD remission rates compared to those receiving a DBT-based treatment (DBT-bt). Again, PTSD remission was accompanied by BPD remission, but not nice versa, suggesting that alleviating PTSD symptoms may facilitate broader improvements. These effects were maintained at 12-month follow-up, with 33.3% of NET participants in remission compared to only 6.2% in the DBT-bt group. This may stem from improvements in PTSD-related intrusions, which often contribute to emotional distress and maladaptive coping. By targeting these disturbances and dissociation, NET may help strengthen emotion regulation abilities. Notably, NET did not exacerbate symptoms, suicide attempts, or self-harm during or after the exposure period, aligning with findings that trauma-focused interventions do not elevate these risks and may even reduce suicidality and hospitalization in individuals with BPD-PTSD [18, 24]. However, a small number of participants reliably worsened at 12-months follow-up compared to baseline, indicating greater variability in response to NET. Nonetheless, the high acceptance and low dropout rates suggest that trauma-focused approaches may promote treatment engagement, an important finding given the barriers many comorbid patients face in sustaining inpatient and outpatient care [25].

Similarly, Pabst et al. [20] found that positive treatment outcomes can be achieved using NET, even with less training and fewer sessions than the standard intervention. A team of clinicians, following just two days of basic NET training, achieved marked improvements in BPD patients with comorbid PTSD. After treatment, patients reported significant reductions in both BPD and PTSD symptoms, as well as in dissociation and depression. While treatment by experts for BPD (TBE) also led to improvements across these domains, the two approaches differ in their underlying mechanisms. TBE, requiring extensive training in DBT and other modalities, focuses on teaching coping strategies and enhancing self-regulation, which may only offer temporary symptom relief. NET, on the other hand, directly targets the associative fear structure, resulting in more enduring reductions in PTSD and dissociative symptoms. This may, in turn, foster stabilization and emotion regulation, ultimately reducing overlapping BPD symptoms. By enabling patients to consciously process traumatic experiences, NET may be particularly effective for patients in this population.

Eye movement desensitization and reprocessing (EMDR) is an established treatment for PTSD. An open pilot study found that adding EMDR to TAU led to significant reductions in PTSD symptom severity, dissociation, and insomnia in patients with personality disorders and co-occurring PTSD. 40% of participants reported PTSD severity scores below the clinical threshold, with no significant differences between those with BPD and other PDs. Despite these improvements, average PTSD severity scores remained elevated, likely due to the high prevalence of childhood trauma in the sample (82%). Repeated trauma exposure may hinder full remission through EDMR, and the limited course of eight sessions may not adequately address the needs of individuals with extensive trauma histories [26].

Using a multiple baseline design, Wilhelmus et al. [27] also found that incorporating EMDR led to reductions in self-reported PTSD symptom severity, which were maintained after treatment discontinuation, an effect not observed in the TAU condition. Similar improvements were observed in measures of general psychopathology, with patients reporting better functioning and social engagement. These findings suggest that EMDR can produce lasting benefits for PTSD symptoms, overall mental health, and day-to-day functioning. That said, the study also only included eight sessions, acknowledging that this may be insufficient for comorbid patients who have experienced multiple traumatic events. While EMDR can be integrated into the early stages of BPD treatment, further research with comorbid samples and additional EMDR sessions is needed.

Integrated treatments

A pilot RCT by Harned et al. [28] evaluated the feasibility and acceptability of standard DBT with and without the addition of a prolonged exposure (PE) protocol in suicidal and self-injuring women with BPD-PTSD. Both groups reported positive attitudes and high satisfaction with treatment, with a substantial majority (73.1%) expressing a preference for the combined DBT + PE approach, countering the assumption that exposure-based treatments are poorly accepted by individuals with SMI. While both groups demonstrated significant reductions in PTSD severity, participants receiving DBT + PE experienced greater improvements over time. Among those who completed the interventions, 80% of DBT + PE participants no longer met criteria for PTSD at post-treatment, compared to 40% of DBT-only completers, and they were 1.3 times more likely to report clinically significant gains. Remission effects in the DBT-only group diminished by the three-month follow-up. Importantly, 80% of patients in the DBT-only group eventually reached the stability required to begin DBT + PE, on average within five months, highlighting DBT’s capacity to prepare patients for trauma-focused treatment and potentially reduce premature dropout.

A series of secondary analyses based on this pilot further explored treatment outcomes and mechanisms of change. One analysis [19] found that DBT + PE led to greater improvements in participants’ ability to maintain social roles and relationships (global social adjustment), self-reported health-related quality of life, and overall daily functioning compared to DBT alone, largely driven by reductions in PTSD severity and maladaptive post-traumatic cognitions (PTCs). While decreases in PTSD severity predicted broader improvements across these domains, changes in PTCs were specifically linked to gains in interpersonal functioning and quality of life. However, DBT + PE did not outperform DBT in these latter domains, suggesting that BPD-related beliefs and negative self-perceptions may exert a stronger influence on social and functional outcomes. These findings align with existing research indicating that PTSD avoidance and numbing symptoms can disrupt social adjustment and everyday functioning.

Across the three stages of DBT treatment, PTSD symptoms did not significantly improve until Stage 2, when the PE protocol was introduced following initial stabilization in Stage 1. This supports staged-based treatment models emphasizing behavioural control and skills acquisition prior to trauma processing. In Stage 3, focused on enhancing quality of life and addressing residual problems, both BPD severity and state dissociation declined, suggesting that these improvements may depend on effective PTSD treatment. Although DBT and DBT + PE produced similar outcomes during Stage 1, differences emerged later, with DBT + PE participants reporting significantly greater global well-being. These findings highlight the added value of directly targeting PTSD to improve comorbid symptoms [29]. Finally, between-person differences in PTCs, shame, ED, and experiential avoidance (EA) were associated with greater PTSD severity and slower symptom improvement, indicating that these factors may be important targets early in DBT to enhance later DBT + PE outcomes. Furthermore, while PTSD severity did not predict subsequent changes in shame, guilt, or ED, it was associated with increases in ED and, to a lesser extent, PTCs, supporting the notion that PTSD can exacerbate BPD-related difficulties, particularly in emotion regulation and management of self-injurious behaviour [10].

The benefits of DBT PE have also been observed in veterans. An intensive outpatient program (IOP) led to significant reductions in PTSD symptoms and improvements in positive coping in response to stressful events (e.g., emotion regulation). Moreover, there were no increases in self-harm, suicide attempts, hospitalizations, or dissociation. Notably, the majority of veterans who had previously been unable to participate in or complete trauma-focused therapy successfully were able to successfully complete treatment. These clinically meaningful outcomes suggest that DBT PE is feasible and effective treatment for this group, challenging the hesitancy to treat veterans with this comorbidity [30].

Prolonged exposure can also be integrated with other trauma-focused interventions. Kolthof et al. [31] found that an eight-day inpatient program combining PE and EMDR led to significant decreases in both BPD and PTSD symptoms. These effects were maintained post-treatment, at 6-month follow-up, and again after 12 months, with no adverse effects or symptom worsening reported. Despite high attrition during the follow-up period, 70% of patients no longer met diagnostic criteria for PTSD, and 73% no longer met criteria for BPD. These findings suggest that integrating evidence-based trauma-focused treatments can be effective for individuals with BPD-PTSD, even without prior stabilization.

DBT-PTSD, a modified version of DBT specifically designed to address both BPD and PTSD, has shown promise for treating individuals with this comorbidity. In a study comparing DBT-PTSD to cognitive processing therapy (CPT), it was found that both groups experienced reductions in BPD and PTSD symptoms over time. However, the DBT-PTSD group showed significantly greater improvements in severity (60% vs. 28%), as well as notable improvements in maladaptive behaviours and dissociations, which was not observed in the CPT group. These findings further suggest that incorporating trauma-focused elements may be especially beneficial for individuals in this population [8, 18].

Discussion

Although prevalence estimates of comorbid BPD-PTSD vary considerably, they consistently indicate relatively high rates across clinical populations. Individuals with this comorbidity often experience higher baseline clinical severity compared to those with BPD-only, and multiple forms of interpersonal trauma, with CSA frequently reported as a primary predictor of severity. This association may be especially relevant among males. In terms of diagnostic conceptualization, while the majority of current research, including latent class [32–35], SEM [36], and cohort [37, 38] studies, supports the classification of BPD, PTSD, and CPTSD as separate constructs, debate persists regarding whether these disorders are best understood categorically or dimensionally. This disagreement is fueled by substantial symptom overlap, shared trauma histories, and high comorbidity rates. Additional research is needed to better understand the prevalence of BPD-PTSD across both clinical and community samples, and to further investigate CSA as a key etiological factor in the development of this comorbidity.

It is commonly assumed that multiple co-occurring disorders lead to poorer outcomes across various domains of emotional and psychological functioning. However, emerging psychotherapy research indicates that individuals with comorbid BPD-PTSD can benefit significantly from treatment and achieve similar outcomes to those with either disorder alone. While this may require incorporating additional trauma-focused or ER components, centering interventions on PTSD symptoms and heightened ED appears essential for patients to experience meaningful benefits. Trauma-focused and integrated treatments appear to be well-accepted and effective in targeting both BPD and PTSD symptomology, challenging the hesitancy to use exposure-based interventions in this high-risk subgroup. These treatments may also help reduce dissociative symptoms, which could serve as a mechanism for broader symptom improvement.

This narrative review captures the significant progress that has been made regarding the treatment responsiveness of comorbid BPD-PTSD. Other common BPD comorbidities, such as eating disorders and alcohol-use disorder [39], may prove to be responsive to integrated psychotherapies and urgently deserve study. In addition, this research points to the salience of targeting ED and suggests that studying treatment processes may uncover relevant mechanisms of change for common BPD comorbidities.

Limitations

Several limitations in the literature were identified. The majority of studies consisted of predominantly or exclusively female participants, reflecting both the historically higher prevalence of BPD among women in clinical samples and the challenges associated with recruiting men for clinical research. Greater attention, time, and resources should be devoted to improving male representation in BPD-PTSD studies to better understand gender differences in this comorbidity. Another key limitation is that none of the studies employed longitudinal designs or examined the role of psychopharmacological interventions. Future treatment research should adopt longitudinal and controlled methodologies and investigate the effectiveness of medications in BPD-PTSD populations. Beyond these literature gaps, this review excluded non-English language studies, which may have led to the omission of relevant data. Additionally, some included papers were secondary analyses of overlapping datasets, raising the possibility that certain participants or results were represented more than once. Finally, the use of a narrative synthesis approach prevented formal quantitative analyses, limiting the ability to statistically assess heterogeneity or publication bias.

Conclusions

Research in this area has expanded considerably over the past decade, reflecting growing recognition of the complexity and clinical importance of BPD-PTSD comorbidity. However, important gaps remain. Given that this comorbidity is treatment-responsive, both patients and clinicians may adopt more optimistic attitudes toward the engagement with and effectiveness of evidence-based interventions. Future research should prioritize the direct targeting of PTSD symptoms and further investigate the central role of emotion regulation in reducing both PTSD and BPD symptomology. Addressing these areas is critical for improving outcomes in this highly burdened population.

Abbreviations

BPD

Borderline personality disorder

PTSD

Post-traumatic stress disorder

CPTSD

Complex PTSD

ED

Emotional dysregulation

CSA

Child sexual abuse

MST

Military sexual trauma

PD

Personality disorder

RCT

Randomized controlled trial

DBT

Dialectical behavioural therapy

MBT

Mentalization-based therapy

NSSI

Non-suicidal self-injury

TAU

Treatment as usual

CBT

Cognitive behavioural therapy

SMI

Severe mental illness

NET

Narrative exposure therapy

TBE

Treatment by experts

EMDR

Eye movement desensitization and reprocessing

PE

Prolonged exposure

PTCs

Post-traumatic cognitions

CPT

Cognitive processing therapy

Author contributions

PSL conceptualized the review and supervised the project. MO conducted the literature search and data extraction. MO and PSL jointly screened the search results, analyzed the data, and drafted the manuscript. All authors read and approved the final version.

Funding

Not applicable.

Data availability

Not applicable. All data analyzed in this review are from previously published studies, which are cited in the article.

Declarations

Ethics approval and consent to participate

Not applicable

Consent for publication

Not applicable. This study does not involve human participants.

Competing interests

The authors declare no competing interests.