Eye movement desensitization and reprocessing therapy in persons with personality disorders: a randomized clinical trial

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

Objective
To evaluate the effectiveness of eye movement desensitization and reprocessing (EMDR) therapy in reducing PD symptoms compared with a waiting list, regardless of PTSD status.

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

Intervention
Ten 90-minute EMDR sessions for 5 weeks, targeting traumatic and adverse memories linked to PD symptoms.

Main Outcomes and Measures
Pretreatment, posttreatment, and 3-month follow-up assessments 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
Among the 159 patients included in the analysis, mean (SD) age was 35.4 (12.0) years, and 130 were female (81.8%). Seventy-nine participants were randomized to the EMDR group and 80 to the waiting-list control group. Four participants (5.1%) dropped out of the EMDR group, and 16 (20.3%) were early completers, without adverse events. EMDR therapy outperformed the waiting-list condition for ADP-IV post treatment (β, −37.93 [95% CI, −52.54 to −23.33]; P < .001; Cohen d = 0.31 [95% CI, −0.05 to 0.66]) and at follow-up (β, −45.73 [95% CI, −64.90 to −26.56]; P < .001; Cohen d = 0.46 [95% CI, 0.10-0.82]), SCID-5-PD post treatment (β, −3.65 [95% CI, −5.87 to −1.42]; P = .002; d = 0.48 [95% CI, 0.14-0.82]) and at follow-up (β, −3.70 [95% CI, −7.10 to −0.30]; P = .03; Cohen d = 0.61 [95% CI, 0.25-0.97]), LPFS post treatment (β, −3.13 [95% CI, −4.86 to −1.41]; P < .001; Cohen d = 0.31 [95% CI, −0.05 to 0.67]) and at follow-up (β, −3.62 [95% CI, −5.96 to −1.28]; P = .003; Cohen d = 0.43 [95% CI, 0.06-0.79]), and DERS post treatment (β, −9.03 [95% CI, −14.90 to −3.15]; P = .003; Cohen d = 0.35 [95% CI, −0.01 to 0.71]) and at follow-up (β, −11.73 [95% CI, −19.90 to −3.55]; P = .005; Cohen d = 0.62 [95% CI, 0.25-0.98]). PD remission was more common in the EMDR than control groups both post treatment (ADP-IV, 38.3% vs 6.8%; SCID-5-PD, 33.3% vs 7.8%) and at 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 of 159 patients with PD, EMDR therapy led to significant reduction in PD symptoms, with 30 (44.1%) achieving remission. These findings support the potential of EMDR therapy for PD treatment and encourage further confirmatory research.