Eye Movement Desensitization and Reprocessing Therapy in Individuals With Personality Disorders – A Randomized Clinical Trial

Authors: Simon Hofman, MSc1,2; Laurian Hafkemeijer, MSc2,3; Ad de Jongh, PhD3,4,5,6,7,8 JAMA Netw Open Published Online: September 25, 2025 2025;8;(9):e2533421. doi:10.1001/jamanetworkopen.2025.33421 Translated by: Specialist Psychologist Elena Gizem Pozam Key Points Question: Does eye movement desensitization and reprocessing (EMDR) therapy reduce personality disorder (PD) symptoms regardless of posttraumatic stress disorder status?

Findings: In this randomized clinical trial involving 159 patients diagnosed with PD, EMDR therapy was superior to a waitlist control condition in reducing PD symptoms at posttreatment and follow-up. At both time points, PD remission was significantly more common in the EMDR group than in the control group.

Meaning: In this study, EMDR therapy demonstrated clinically meaningful reductions in PD symptoms, with nearly half of participants achieving diagnostic remission. This supports the potential of EMDR as an effective intervention for PDs.

Abstract Importance: Adverse childhood experiences contribute to the development of personality disorders. Although trauma-focused interventions are effective for posttraumatic stress disorder (PTSD), their effects on PD symptoms are less well established.

Objective: To evaluate the efficacy of EMDR therapy in reducing PD symptoms compared with a waitlist condition, regardless of PTSD status.

Design, Setting, and Participants: This 2-arm, multicenter, single-blind randomized clinical trial was conducted between February 22, 2021, and October 2, 2024, in specialized outpatient units at 2 clinics in the Netherlands. Participants included 159 patients diagnosed with PD using the Structured Clinical Interview for DSM-5 Personality Disorders (SCID-5-PD). Data were analyzed on an intention-to-treat basis.

Intervention: Ten 90-minute EMDR sessions over 5 weeks targeting traumatic and adverse memories associated with PD symptoms.

Main Outcomes and Measures: Pretreatment, posttreatment, and 3-month follow-up assessments were conducted using the Assessment of DSM-IV Personality Disorders (ADP-IV), SCID-5-PD, Level of Personality Functioning Scale (LPFS), and Difficulties in Emotion Regulation Scale (DERS).

Results: The 159 patients included in the analysis had a mean age of 35.4 (SD: 12.0) years, and 130 (81.8%) were women. Seventy-nine participants were randomly assigned to the EMDR group and 80 to the waitlist control group. In the EMDR group, 4 participants (5.1%) dropped out of treatment and 16 (20.3%) completed treatment early; no adverse effects were observed. EMDR therapy was more effective than the waitlist condition for ADP-IV at posttreatment (β, −37.93 ; P < .001; Cohen d = 0.31 ) and follow-up (β, −45.73 ; P < .001; Cohen d = 0.46 ), SCID-5-PD at posttreatment (β, −3.65 ; P = .002; d = 0.48 ) and follow-up (β, −3.70 ; P = .03; Cohen d = 0.61 ), LPFS at posttreatment (β, −3.13 ; P < .001; Cohen d = 0.31 ) and follow-up (β, −3.62 ; P = .003; Cohen d = 0.43 ), and DERS at posttreatment (β, −9.03 ; P = .003; Cohen d = 0.35 ) and follow-up (β, −11.73 ; P = .005; Cohen d = 0.62 ). PD remission was more common in the EMDR group at both posttreatment (ADP-IV, 38.3% vs 6.8%; SCID-5-PD, 33.3% vs 7.8%) and follow-up (ADP-IV, 45.4% vs 5.9%; SCID-5-PD, 44.1% vs 15.8%).

Conclusions and Relevance: In this randomized clinical trial involving 159 patients diagnosed with PD, EMDR therapy led to significant reductions in PD symptoms, and 30 patients (44.1%) achieved remission. These findings support the potential of EMDR therapy in the treatment of PD and encourage further confirmatory research.

Registration: Netherlands Trial Register: NL9078

Introduction Personality disorders (PDs) are a significant public health concern, affecting approximately 12% of the general population and up to 50% of psychiatric outpatients. PDs cause serious difficulties for individuals and affect their families and communities, increasing societal costs. Although psychotherapy is an effective first-line treatment, it generally requires a long-term commitment, often lasting at least 1 year, particularly for individuals with clinical or subclinical borderline PD.

Given the association between adverse childhood experiences and the development of PD, trauma-focused therapy has attracted interest as a potential treatment for PDs. Research shows that trauma-focused therapies significantly reduce PTSD symptoms in patients with comorbid borderline PD and PTSD (Hedges g range, 1.04-1.31), with very few adverse effects. Furthermore, treatment of PTSD in patients with comorbid PD has been found to be safe and effective (Hedges g = 0.52), with adverse effects reported rarely and at low severity.

EMDR therapy is a well-established treatment for processing traumatic memories and shows promise in reducing psychological distress and improving functioning in individuals with PD, even in the absence of comorbid PTSD. A randomized clinical trial in patients with PD without comorbid PTSD showed that 5 EMDR sessions targeting adverse childhood experiences, such as emotional abuse or neglect, led to a moderate reduction in Brief Symptom Inventory scores (Cohen d = 0.65) and improvement in personality functioning (Cohen d = 0.56), with no adverse effects and less symptom exacerbation than in a waitlist control group. However, that study did not assess PD symptom severity, diagnostic remission, or the severity of emotion dysregulation and provided only 5 weekly EMDR sessions.

To address these gaps and advance the development of a brief and effective treatment approach for PDs, the present study investigated the efficacy of EMDR therapy for PDs regardless of the presence of PTSD. The primary objective was to determine whether EMDR therapy significantly reduced PD symptoms compared with a waitlist control condition. We hypothesized that EMDR therapy would lead to a significant reduction in PD symptom severity compared with the control condition. Secondary objectives included assessing diagnostic remission, changes in personality functioning, and difficulties in emotion regulation.

Methods Design This study was part of the Trauma-focused EMDR for Personality disorders among Outpatients (TEMPO) study, a 2-arm, multicenter, single-blind, superiority randomized clinical trial. The study protocol (Supplement 1) was prepared in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines, approved by the Medical Research Ethics Committee of Erasmus Medical Center in Rotterdam, and previously published. All participants provided written informed consent.

Participants A total of 159 participants were recruited from the outpatient clinics of 2 mental health institutions in the Netherlands: Parnassia Psychiatric Institute (The Hague) and GGZ Delfland (Delft). Eligible participants had to be aged 18 years or older and diagnosed with any PD using the SCID-5-PD. Patients diagnosed with other specified PD were required to have at least 10 PD symptoms. Exclusion criteria were insufficient Dutch language proficiency or an estimated IQ below 70. A power analysis determined that a total of 132 participants were needed to detect the treatment effect on PD symptom severity using linear mixed models, assuming an effect size of Cohen d = 0.43, a correlation between repeated measures of 0.70, α = .05, and power = 0.80. Allowing for 20% data loss, the final sample comprised 159 participants.

Measures Assessments were conducted at baseline, posttreatment, and 3-month follow-up. Assessors (including S.H.) attended standardized external training sessions to ensure consistency in administering structured interviews. All outcome assessments were conducted blind to treatment allocation, and assessors were not involved in treatment. The primary measure was the Assessment of DSM-IV Personality Disorders (ADP-IV), which provides an overall severity score and allows categorical PD diagnosis. Secondary measures included the SCID-5-PD, a semistructured interview used to assess DSM-5 PDs; the Level of Personality Functioning Scale–Brief Form 2.0 (LPFS), which assesses personality functioning based on the alternative DSM-5 model; and the Difficulties in Emotion Regulation Scale (DERS), a self-report measure developed to assess clinically relevant difficulties in emotion regulation. Hofman et al. provide the study design and an overview of the measures.

Methods Procedure Recruitment for this study took place between February 22, 2021, and April 9, 2024, and data collection was completed on October 3, 2024. Participants were recruited through: (1) posters displayed in outpatient clinic waiting rooms, (2) direct referrals from therapists, and (3) direct contact by researchers with patients who had consented to being contacted for research purposes. Recruitment emphasized that individuals with any PD could participate, regardless of the presence of PTSD or traumatic memories. Interested individuals received detailed information about the study and were screened for eligibility by the research team before informed consent was obtained. Randomization was performed using a pregenerated random sequence (1:1 allocation without blocks) in the ResearchManager electronic data capture system. This independent external platform was used for secure data management. Allocation was concealed from blinded researchers; only unblinded researchers (including S.H. and L.H.) and the principal investigator (C.W.S.) could access allocation through a restricted interface. Details of the procedure are available in Hofman et al. Participants in the waitlist condition did not receive trauma-focused or PD treatment, and their medication regimens remained unchanged, although interim contact was available when needed. For all participants, the therapist who conducted the initial diagnostic assessment met with the participant after the 3-month follow-up to assess the need for further treatment.

Treatment Half of the participants received 10 EMDR sessions, delivered twice weekly over 5 weeks, with each session lasting 90 minutes. Treatment was based on a structured case conceptualization. Sessions initially targeted traumatic memories meeting PTSD Criterion A, prioritizing intrusive memories over nonintrusive memories. Therapy focused on memories associated with the patient's most prominent PD symptoms. The standard EMDR protocol was used, while EMDR 2.0 incorporated a higher working memory load. Anticipatory fears that interfered with treatment were addressed using the flashforward protocol. Participants who no longer met PD diagnostic criteria during the treatment phase according to their ADP-IV score were defined as early completers.

Supervision and Adherence Monitoring EMDR therapy was delivered by certified therapists who had completed accredited Basic EMDR training in the Netherlands. Before the study, all therapists attended an additional 1-day training session delivered by an EMDR Europe Association (EMDREA)–accredited trainer. Therapists reported each case conceptualization and EMDR session to an EMDREA-approved consultant using a specially designed form. This form included information on target memories and subjective units of distress levels before and after sessions, time spent fully reprocessing memories, and overall session summaries. Monthly group supervision was provided by EMDREA-approved consultants, during which video recordings of EMDR sessions were presented. Additional supervision was available on request. All sessions were video-recorded, and for 20% of participants, a randomly selected session was rated by assessors blinded to treatment outcomes. Protocol adherence was high, with a mean score of 9.8 out of 11 ( 89.5% ), and 100% of sessions scored at least 8.

Statistical Analysis Data were analyzed using IBM SPSS version 27 and R version 4.3.3, with the nlme and lme4 packages. Primary and secondary outcomes were evaluated using linear mixed models (LMMs). Each model included fixed effects for group (EMDR vs control), time (baseline, posttreatment, and follow-up), the group × time interaction, and baseline severity, as well as a random intercept for participants and a random slope for time. Models were estimated using restricted maximum likelihood with an autoregressive covariance structure to account for temporal correlations between repeated measures. This approach incorporated all available data under the assumption that data were missing at random and ensured that all randomized participants were included in the analysis in accordance with the intention-to-treat principle.

To facilitate interpretation, within-group and between-group Cohen d effect sizes were reported for descriptive purposes only. Within-group effect sizes indicated the magnitude of change over time in each condition, while between-group effect sizes indicated group differences at posttreatment and follow-up. Cohen d was calculated by dividing the mean difference (within or between groups) by the pooled standard deviation. Effect sizes were classified as small (0.20), medium (0.50), and large (0.80). A 2-sided significance level of α = .05 was applied to all statistical tests.

Generalized linear mixed models (GLLMs) were used to test whether PD remission according to the ADP-IV was more common in the EMDR group than in the control group. In addition to the group × time interaction, models included main effects for group (2 levels: EMDR vs control) and time (3 levels: baseline, posttreatment, follow-up) and a random effect controlling for within-participant variance. Because a SCID-5-PD diagnosis was required for study inclusion, all participants (100%) had a PD diagnosis at baseline, and the GLMMs therefore failed to converge. Consequently, to compare SCID-5-PD–based PD remission, chi-square tests were conducted at posttreatment and 3-month follow-up using group (2 levels: EMDR vs control) and PD diagnosis (2 levels: yes vs no), with Bonferroni correction for multiple testing. Odds ratios (ORs) were calculated to quantify effect size.

To assess the robustness of the findings, sensitivity analyses were conducted using completer-only analyses (SCID-5-PD, 122; ADP-IV, 113; LPFS, 107; DERS, 107) and multiple imputation (MI) with the mice package in R. MI generated 35 datasets over 50 iterations, accounting for the multilevel data structure. Estimates and standard errors were pooled using Rubin's rules.

Results As shown in the Figure, 159 participants (mean age: 35.4 [12.0] years; 130 women [81.8%], 29 men [18.2%]) were randomly assigned to receive EMDR therapy (n = 79) or to the waitlist control group (n = 80). Outcome data were available for 137 participants (86.2%) at posttreatment and 127 (79.9%) at follow-up. Table 1 presents baseline demographic and clinical characteristics, which were well balanced between groups.

Of the 79 EMDR participants, 4 (5.1%) dropped out of treatment. No adverse effects were reported. In total, 25 participants (31.6%) fully processed all target memories before completing all EMDR sessions. Of these, 16 (20.3%) no longer met PD diagnostic criteria according to the ADP-IV and were classified as early completers. A total of 25 participants (15.7%) deviated from the medication stabilization protocol. These deviations were evenly distributed, involving 13 participants (16.5%) in the EMDR group and 12 (15.0%) in the control group.

Intention-to-Treat Analyses LMMs revealed significant group × time interaction effects across all primary and secondary outcomes (Table 2). This finding indicates greater improvements in PD symptom severity, personality functioning, and emotion regulation in the EMDR group than in the control group. Specifically, EMDR therapy was superior to the waitlist condition for ADP-IV at posttreatment (β, −37.93 ; P < .001; Cohen d = 0.31 ) and follow-up (β, −45.73 ; P < .001; Cohen d = 0.46 ); SCID-5-PD at posttreatment (β, −3.65 ; P = .002; Cohen d = 0.48 ) and follow-up (β, −3.70 ; P = .03; Cohen d = 0.61 ); LPFS at posttreatment (β, −3.13 ; P < .001; Cohen d = 0.31 ) and follow-up (β, −3.62 ; P = .003; Cohen d = 0.43 ); and DERS at posttreatment (β, −9.03 ; P = .003; Cohen d = 0.35 ) and follow-up (β, −11.73 ; P = .005; Cohen d = 0.62 ). Completer-only sensitivity analyses showed similar results. Model comparisons (χ2<0.01; P = .99) and interaction tests indicated that site differences did not influence treatment outcomes.

The initial MI included all available data (N = 159) and yielded model estimates (β coefficients) consistent with the primary analyses. However, reduced degrees of freedom in MI decreased power and increased P values; this was attributed to participants with baseline data only (n = 19; mostly from the control group ), EMDR dropouts (n = 4), and 1 early completer. This pattern suggests that data may have been missing not at random rather than completely at random. A second MI excluding these 19 cases (n = 140) yielded estimates, degrees of freedom, and P values consistent with the primary analyses, supporting the robustness of the findings.

Between-group effect sizes ranged from small at posttreatment (Cohen d = 0.31-0.48) to small to medium at follow-up (Cohen d = 0.43-0.62) (Table 2). In the EMDR group, improvements increased from small to medium between baseline and posttreatment (Cohen d = 0.45-0.76) to medium to large between baseline and follow-up (Cohen d = 0.76-0.98) (Table 2). Although effect sizes in the EMDR group varied from small to large across diagnostic subgroups, they generally indicated consistent benefits across different PDs (Table 3).

A GLLM revealed a significant group × time interaction; the reduction in ADP-IV diagnoses in the EMDR group was greater than in the control group from baseline to posttreatment ( 38.3% vs 6.8%; β = −2.27 ; P = .003; OR, 0.10 ) and from baseline to 3-month follow-up ( 45.4% vs 5.9%; β = −2.90 ; P < .001; OR, 0.06 ). SCID-5-PD diagnoses also decreased more in the EMDR group than in the control group at posttreatment (24 [33.3%] vs 5 [7.8%]; χ21 = 11.68 ; P < .001; OR, 0.17 ) and follow-up (30 [44.1%] vs 9 [15.8%]; χ21 = 10.31 ; P = .001; OR, 0.24 ) (Table 4). Completer-only sensitivity analyses yielded similar results.

Discussion This randomized clinical trial evaluated the efficacy of stand-alone EMDR therapy for PD, regardless of comorbid PTSD, compared with a waitlist control condition. Results showed significant reductions in PD symptom severity at posttreatment and 3-month follow-up, diagnostic remission in 44.1% of participants, and improvements in personality functioning and emotion regulation. These effects were consistent across PD subtypes and among patients with and without a PTSD diagnosis at baseline. The dropout rate was low (4 [5.1%]), and no adverse effects were reported.

These findings contribute to a growing body of evidence supporting trauma-focused interventions, including stand-alone approaches, in the treatment of PD. The results are consistent with previous studies showing that trauma-focused therapy may be effective in PD populations even without PTSD. The present study extends the literature by systematically examining PD symptom severity, diagnostic remission, and emotion dysregulation, providing strong evidence that EMDR therapy is a safe and effective stand-alone intervention regardless of comorbid PTSD. While previous studies have largely focused on treating borderline PD, typically through long-term psychotherapeutic interventions, the present study shows that targeting memories of traumatic and adverse events with EMDR can produce clinically meaningful improvements across a broad range of PDs. The results align with theoretical models that conceptualize maladaptive personality traits as arising from unresolved traumatic experiences and reinforce the emerging view that trauma-focused therapies may be beneficial beyond traditional PTSD populations.

Recommendations These findings suggest that EMDR therapy may be a useful starting point in PD treatment, particularly given the substantial reductions in PD symptom severity and diagnostic status observed following a brief intervention. Given the continued improvements at follow-up, reassessing the need for additional treatment 3 months after therapy may be appropriate. Some patients may benefit sufficiently from EMDR therapy alone, while others may require additional interventions. Future research should evaluate the long-term effects of EMDR and compare them with active controls, such as standard PD treatments or alternative trauma-focused treatments. This may help clarify the specific contribution of EMDR therapy and reduce potential expectancy effects. The optimal delivery of EMDR therapy should be investigated by examining variables such as the number, frequency, and timing of sessions to maximize therapeutic outcomes.

Strengths and Limitations This study has several strengths: a high retention rate, the use of both dimensional and categorical assessments of PDs, the inclusion of individuals with and without PTSD, and a broad range of PDs, including less-studied types such as avoidant or other specified PDs, which enhances the ecological validity of the findings. Effect sizes provide quantitative benchmarks for comparison with previous research.

However, several limitations should also be noted. First, the waitlist control condition not only limits the ability to attribute treatment effects directly to EMDR therapy but also restricts estimation of the true effect size. Recent meta-analytic evidence from depression research indicates that waitlist-controlled studies produce higher effect sizes than studies using usual-care controls, largely due to the smaller pretreatment-to-posttreatment changes observed in waitlist conditions. In addition, using a waitlist group may create expectancy effects that could reduce observed group differences because participants know they will eventually receive the intervention. Nevertheless, we believe future research should include active or usual-care control conditions to enhance internal and external validity. Second, double blinding (e.g., sham EMDR) was not feasible, potentially increasing expectancy effects. Third, significant improvements over time were also observed in the control group, which may reflect the effect of study participation itself. Fourth, although the diagnostic instruments used in this study (ADP-IV and SCID-5-PD) were designed to assess enduring personality pathology, a 3-month follow-up is a relatively short period for assessing sustained change. Fifth, although the sample included a broad range of PDs, most participants had avoidant, borderline, obsessive-compulsive, or other specified PD, limiting generalizability to less common PD types. Finally, although benefits persisted for at least 3 months, long-term effects remain unknown.

Conclusions This randomized clinical trial supports the potential of trauma-focused approaches such as EMDR therapy in the treatment of personality pathology. Further research, including direct comparisons with established psychotherapeutic interventions for PDs, is needed to confirm and extend these findings.

Article Information Accepted for Publication: July 25, 2025.

Publication Date: September 25, 2025. doi:10.1001/jamanetworkopen.2025.33421

Open Access: This is an open-access article distributed under the terms of the CC-BY License. © 2025 Hofman S et al. JAMA Network Open.

Corresponding Author: Simon Hofman, MSc, Lijnbaan 4, 2512VA Den Haag, Netherlands (s.hofman@parnassiagroep.nl).

Author Contributions: Mr. Hofman and Dr. Slotema had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the analyses.

Concept and design: All authors. Acquisition, analysis, or interpretation of data: All authors. Drafting of the manuscript: All authors. Critical review of the manuscript for important intellectual content: Hafkemeijer, de Jongh, Slotema. Statistical analysis: Hofman. Obtained funding: Hofman. Administrative, technical, or material support: Hofman, Hafkemeijer. Supervision: de Jongh, Slotema.

Conflict of Interest Disclosures: Hafkemeijer reported receiving support from GGZ Delfland, Parnassia Psychiatric Institute, Vereniging EMDR Nederland, and EMDR Europe during the conduct of the study, as well as grant support from Vereniging EMDR Nederland outside the submitted work. Hafkemeijer reported receiving training fees for postgraduate courses on EMDR therapy outside the study. Dr. de Jongh reported receiving training fees for postgraduate courses on EMDR therapy and personal fees related to authorship of books on EMDR, and serving as a board member of the Dutch EMDR Association and the EMDR Europe Association. No other conflicts of interest were reported.

Funding/Support: The study was funded internally by Parnassia Psychiatric Institute and GGZ Delfland and supported externally by Vereniging EMDR Nederland, EMDR Europe, and the EMDR Research Foundation.

Role of the Funders: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication.

Data Sharing Statement: See Supplement 2.

Additional Contributions: We thank Mathijs Deen, MSc, of Parnassia Psychiatric Institute for consultation on statistical analyses, and Annemieke Driessen, MSc, of Faas Psychologie and Yvonne Merkies, MSc, of Sinai Centrum for supervision of EMDR therapy. No compensation was provided for these contributions.

Statement on the Use of Artificial Intelligence: The authors used ChatGPT-4 (via chat.openai.com; April-July 2025; developed by OpenAI, San Francisco, California) for language refinement and stylistic editing. The tool was used primarily to improve clarity, grammar, and writing quality in parts of the Introduction and Discussion sections. All intellectual content, analyses, and conclusions are the authors' own. The authors take full responsibility for the integrity and accuracy of the content.

References