Intrusive Memories of Traumatic Event(s)

Post-Traumatic Stress Disorder (PTSD) and trauma-related symptoms are often characterized by recurrent intrusive memories that cause distress and interfere with daily functioning. Although trauma-focused interventions such as Eye Movement Desensitization and Reprocessing (EMDR) may be effective, they often involve engagement with trauma-related memories, which can be distressing for some individuals and may affect treatment acceptability. This randomized controlled trial will evaluate a standardized eye-movement-based procedure for trauma-exposed individuals experiencing recurrent intrusive memories. Participants will be randomly assigned to one of several memory-related task conditions involving eye movements. The study will assess the frequency and distress of trauma-related intrusive memories at prespecified assessment points, as well as PTSD symptoms, intervention-related distress, acceptability, and safety. Findings from this trial may help inform the development of tolerable approaches for targeting trauma-related intrusive memories.

Intrusive traumatic memories frequently trigger severe distress and psychological disorders like PTSD. Traditional therapies require explicit trauma recall, which often causes severe patient distress and leads to treatment avoidance. To address this, our study introduces a novel, less aversive intervention combining unconscious visual processing with bilateral eye movement to mitigate these intrusive memories. Utilizing a randomized, three-arm design (comparing standardized trauma-related images, patient-provided images, and neutral images, all paired with bilateral eye movements), we plan to recruit participants who have experienced severe trauma and report ≥ 5 intrusive memories weekly, targeting a final sample of 40 patients per arm. The primary outcome is the frequency of intrusive memories. Secondary and additional outcomes include PTSD severity (CAPS-5, PCL-5, IES), depression, anxiety, borderline symptoms, functional improvements, subjective intervention distress, and dropout rates.

Post-Traumatic Stress Disorder (PTSD) is characterized by recurrent, intrusive memories of traumatic events that cause significant distress and functional impairment. Although trauma-focused treatments are effective, they typically require deliberate recollection of traumatic experiences, which can be distressing and may contribute to treatment avoidance or dropout. In previous experimental studies conducted with healthy participants, we demonstrated that unconscious reactivation of trauma-related cues, followed-after a brief delay corresponding to the memory reconsolidation window-by a visuospatial interference task (Tetris gameplay), reduced the frequency and emotional intensity of intrusive memories. These findings suggest that memory representations may be modifiable during reconsolidation without requiring conscious recall. Building on this work, the present randomized controlled trial (RCT) aims to evaluate the clinical efficacy and tolerability of this reconsolidation-based intervention in trauma-exposed individuals experiencing five or more intrusive memories per week.

The goal of this clinical trial is to learn if non-invasive neurostimulation of memory-related brain areas works to treat intrusive memory symptoms in adults patients with posttraumatic stress disorder (PTSD). It will also learn about the effect of this neuromodulation procedure on reorganization of memory-related brain networks. The main questions it aims to answer are: Does neuromodulation lower the number of times and the emotional severity participants intrusive memories? Does neuromodulation reduces the overall severity of PTSD? Researchers will compare neuromodulation targeting the hippocampus (a memory-related brain structure) to a control stimulation in an area not related to memory processes to see if hippocampus neuromodulation works to treat intrusive trauma memories and PTSD. Participants will: 1. Undergo magnetic resonance imaging (MRI) scans before and after neuromodulation to: a) determine a personalized neuromodulation target; and b) to measure changes in brain function from before to after treatment. 2. Receive hippocampus neuromodulation or a control neuromodulation once a week for 5 weeks. Keep a daily diary of their symptoms and the number of times they experience intrusive trauma memories.