According to the diagnostic manuals, ‘borderline personality disorder’ (BPD) is a psychiatric condition characterised by an unstable sense of self and difficulties managing intense emotions and maintaining healthy relationships.
Most people diagnosed with BPD also experience depression, anxiety, or both; up to 70% are diagnosed with depression and up to 90% with an anxiety disorder (Söderholm et al. 2024; Qadeer Shah et al. 2023). This overlap can make effective treatment more difficult; depression alongside BPD raises the risk of relapse and suicide attempts, and anxiety alongside BPD has been linked to more severe BPD symptoms (Ceresa et al. 2021; Quenneville et al. 2020).
BPD is more common than people may assume. In England, 1.9% of adults screened positive for BPD in the 2023-24 Adult Psychiatric Morbidity Survey (Clery et al. 2025). Despite this, some clinicians still describe the condition as untreatable, compounding the stigma people with BPD already face.
So, what works for treatment when BPD occurs with depression and/or anxiety? In a systematic review, Francis, Fino and Heym (2026) set out to examine the evidence for three therapies:
Methods
The review team followed PRISMA guidelines and searched five databases, PubMed, PsycINFO, MEDLINE with Full Text, Web of Science and Academic Search Complete for studies evaluating the following three therapies for people with BPD:
- Dialectical Behaviour Therapy (DBT) teaches practical skills for managing intense emotions, tolerating distress and improving relationships
- Mentalisation-Based Treatment (MBT) helps people better understand their own thoughts and feelings, as well as others
- Internal Family Systems (IFS) views the mind as made up of different ‘parts’, helping them work together when trauma disrupts their balance
To be eligible, studies had to include participants aged 12 years or older with BPD and co-existing depression or anxiety, confirmed using a diagnostic manual or clinical interview. Studies were eligible whether participants met full diagnostic criteria or fell below the threshold.
Of 518 studies identified, 12 studies were eligible to be included in the review. Four randomised controlled trials and eight naturalistic studies were included. Ten of the twelve studies looked at DBT, two at MBT, and none at IFS. Study quality was rated using the Downs and Black (1998) checklist, with one study rated ‘excellent’, nine ‘good’ and two ‘fair’.
The studies varied too widely in sample characteristics, outcome measures and intervention modifications to combine statistically, so the findings were synthesised narratively.
Results
The findings were generally positive and fell into four main categories.
Symptoms
- Several DBT studies reported reductions in BPD symptoms, depression and/or anxiety, although findings were not consistent across all studies.
- One DBT study found significant reductions in depression and anxiety, while a waiting-list group showed no change.
- MBT studies reported reductions in BPD and depressive symptoms; neither assessed anxiety.
Emotional and interpersonal difficulties
- DBT improved coping and reduced emotion suppression.
- MBT improved relational functioning and satisfaction with relationships.
Impulsive behaviours
- In one inpatient DBT study, 62% of participants abstained from self-harm, compared with 31% on a waiting list.
- In an 18-month naturalistic MBT study, the proportion reporting at least one suicide attempt fell from 31.7% before treatment to 0% at 12 months, rising slightly to 3% by the end.
Service use
- Two DBT studies reported reductions in emergency department visits, inpatient admissions and length of stay.
- The naturalistic MBT study reported a reduction in the proportion experiencing inpatient admission from 35.6% before treatment to 3% post-treatment.
- Shorter DBT programmes, including interventions lasting eight weeks, also showed benefits. This may be relevant where a 12-month programme is difficult to sustain, although the evidence does not show that brief DBT is equivalent to full-length DBT.
However, findings were not uniformly positive
- One DBT study found no significant change in self-harm. Effects on anger, fear and shame were observed in participants with comorbid anxiety, but not in those with comorbid depression.
- For IFS, not one study met the criteria. Although it is reportedly being used in some UK ‘personality disorder’ services, its efficacy has yet to be tested in this population.
Conclusions
The researchers conclude that DBT and MBT show promising effects across BPD symptoms, depressive and/or anxiety symptoms, emotional and interpersonal difficulties, impulsive behaviours and mental health service use. However, the evidence is limited and heterogeneous. No included study investigated IFS in this patient population.
Benefits were reported with both standard and modified programmes, including shortened DBT interventions, suggesting that briefer DBT may be useful for some service users. The MBT evidence came from longer programmes lasting 12 to 18 months. The authors advised caution because of mixed study designs, small samples, partial comorbidity and limited follow-up, and because effects were not significant across all studies.
The review highlights the high prevalence of comorbid anxiety and depression in people diagnosed with BPD, alongside the limited evidence specifically addressing these combinations. Similarly, the statistic that up to 69% of users accessing IAPT services were estimated to have a high risk of ‘personality disorder’ underscores the importance of recognising and appropriately supporting BPD within UK mental health services.
Strengths and limitations
This review is the first to focus specifically on specialised psychotherapies for service users diagnosed with BPD and comorbid depression and/or anxiety. Despite the prevalence of these disorders in NHS service users, this population has received little attention in the literature. Many reviews treat comorbid depression and anxiety as background disorders, while this review emphasises their clinical importance and impact on BPD. A key strength of this review is filling this research gap and providing evidence of real importance to an under-researched group with complex needs.
Other key strengths of this research include its strong ecological validity. The included studies measured outcomes relevant to NHS service use and treatment cost, including emergency department visits, length of inpatient stay, and subsequent contact with mental health services. These outcomes can help inform service planning, although the mixed designs mean that they should not be interpreted as evidence of cost-effectiveness or causal treatment effects.
There were several limitations to this research. The authors note that many studies included in the review had small sample sizes, lacked long-term follow-up periods and lacked a comparison group, decreasing the overall validity of the study’s conclusions. The authors also note that none of the included studies reported therapist adherence to DBT or MBT treatment manuals, which may affect treatment fidelity and outcomes.
Importantly, except for one study, comorbid depression and/or anxiety was present in only part of the sample, making it difficult to determine whether findings specifically apply to people with BPD and these comorbidities. The studies also varied substantially in samples, outcome measures, treatment formats and intervention length, so the findings could not be combined statistically.
Our reading also identified several areas that could be strengthened. The review was restricted to English-language publications and did not report a grey-literature search, which may increase the risk of language and publication bias. The review also does not report how concurrent medication was handled across studies, making it difficult to judge its potential contribution to changes in depression or anxiety. In addition, no structured patient or public involvement is reported; future reviews could incorporate lived-experience perspectives to strengthen clinical relevance and acceptability.
Implications for practice
This review suggests that DBT and MBT may be useful for individuals with BPD and comorbid anxiety and/or depression, although the evidence is limited. Brief DBT courses may be feasible in time-limited settings, but the evidence does not establish that brief DBT is equivalent to full-length DBT, and the MBT evidence concerns longer programmes.
Despite promising results, the evidence investigating DBT and MBT in these populations is limited. Further randomised controlled trials should control for diagnostic variation and medication use in order to isolate any treatment effects. Finally, although IFS is reportedly used in some NHS services, the evidence base evaluating its safety and effectiveness for this specific clinical population is currently (and according to this study) non-existent. Clinical researchers should aim to evaluate IFS in naturalistic settings to determine whether the use of this intervention is warranted taking into account its feasibility, acceptability, safety and effectiveness before wider implementation.
Given the promising but limited findings, NHS services should consider improving access to evidence-based specialist interventions such as DBT and MBT for people with BPD and comorbid anxiety and/or depression. Brief DBT interventions may be used to maximise time in strained services, and possibly to prevent the development of BPD in adolescents with subsyndromal symptoms and comorbid anxiety and/or depression. Clinicians may choose to seek specialist training to develop their skills in providing DBT and MBT, which is likely to increase acceptability of care by expanding available treatment options.
Statement of interests
None of the authors of this blog had any personal or professional involvement with the study described above, nor any prior contact with any researchers involved in the study’s conduct or dissemination. All authors have received postgraduate training in mental health at University College London, which is unaffiliated with the study authors’ respective institutions. The authors work in mental healthcare in either a voluntary or paid capacity, but deny any other financial interests (e.g., investments) relevant to the study.
Editor
Edited by Dr Dafni Katsampa.
Contributors
Thanks to the UCL Mental Health MSc students who wrote this blog from the Wickersham Student Group: Mary Llamido, Elliot Brewer, and XYZ.
UCL MSc in Mental Health Studies
This blog has been written by a group of students on the Clinical Mental Health Sciences MSc at University College London. A full list of blogs by UCL MSc students can be found here.
We regularly publish blogs written by individual students or groups of students studying at universities that subscribe to the National Elf Service. Contact us if you’d like to find out more about how this could work for your university.
Links
Primary paper
Brandi Francis, Emanuele Fino, Nadja Heym (2026) A systematic review of dialectical behaviour therapy, mentalisation-based treatment and internal family systems therapy for borderline personality disorder with comorbid depression and/or anxiety. Journal of Psychiatric Research 194, 221–232.
Other references
Ceresa A, Esposito CM, Buoli M. (2021) How does borderline personality disorder affect management and treatment response of patients with major depressive disorder? A comprehensive review. Journal of Affective Disorders 281, 581–589.
Clery E, David M, Cretch E, Morris S, Barnicot K, Coid J, McManus S, Moran P. (2025) Personality disorder. In: Morris S, Hill S, Brugha T, McManus S (eds) Adult Psychiatric Morbidity Survey: Survey of Mental Health and Wellbeing, England, 2023/4. NHS England.
Downs SH, 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 and Community Health 52(6), 377–384.
Qadeer Shah A, Prasad D, Caropreso L, Frey BN, de Azevedo Cardoso T. (2023) The comorbidity between Borderline Personality Disorder (BPD) and Generalized Anxiety Disorder (GAD): a systematic review and meta-analysis. Journal of Psychiatric Research 164, 304–314.
Quenneville AF, Kalogeropoulou E, Küng AL, Hasler R, Nicastro R, Prada P, Perroud N. (2020) Childhood maltreatment, anxiety disorders and outcome in borderline personality disorder. Psychiatry Research 284, 112688.
Söderholm JJ, Socada JL, Ekelund J, Isometsä E. (2024) How changes in depression severity and borderline personality disorder intensity are linked — a cohort study of depressed patients with and without borderline personality disorder. Borderline Personality Disorder and Emotion Dysregulation 11(1), 3.