Supplementary Material for: The effectiveness of EMDR Therapy on PTSD symptoms and diagnostic status in patients with a personality disorder: a Randomized Controlled Trial

Background
Individuals with a personality disorder (PD) often report high exposure to adverse events. Given the strong link between negative life events and PD pathology, it is essential to evaluate trauma-focused treatments in this population.
Objective
This study evaluated the effectiveness of EMDR versus waitlist in reducing PTSD symptoms and diagnostic status, distinguishing between patients with and without PTSD. Secondarily, it examined the impact of EMDR on adverse event memories, both meeting and not meeting Criterion A for PTSD.
Method
Participants (n=159) were randomly assigned to EMDR therapy or waitlist. PDs were assessed using the Structured Clinical Interview for DSM-5. PTSD symptoms and diagnoses were evaluated using the Clinician-Administered PTSD Scale for DSM-5. Secondary analyses examined the effectiveness of EMDR on various types of memories.
Results
Significant group-by-time interactions showed a greater reduction in PTSD symptoms in the EMDR group, regardless of baseline PTSD diagnosis. In patients with PTSD, large effects were found post-treatment (d = 1.26; control: d = .28) and at follow-up (d = 1.5; control: d = .69). In patients without PTSD, moderate to large effects emerged post-treatment (d = .77; control: d = .18) and at follow-up (d = 1.09; control: d = .46). EMDR reduced symptoms associated with Criterion A trauma and other adverse events. Post-treatment, 65.5% of EMDR patients lost their PTSD diagnosis, increasing to 73.1% at follow-up.
Conclusions
EMDR effectively reduced PTSD symptoms in individuals with a PD, regardless of PTSD diagnosis, and proved effective for memories not meeting Criterion A.