Brief Manual for Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation Therapy for the Treatment of Post-traumatic Stress Disorder

Abstract

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation (3MDR) is an innovative exposure-based immersive psychotherapeutic intervention for the treatment of post-traumatic conditions such as post-traumatic stress disorder (PTSD) and other related trauma disorders. This manual reviews the theoretical foundations, protocol, and key therapeutic processes of 3MDR, emphasizing its applicability across clinical and research settings. Developed to overcome barriers to traditional trauma-focused psychotherapies, 3MDR combines immersive virtual reality (VR), motion-assisted engagement, and personalized trauma cues to facilitate memory processing and reconsolidation.

3MDR integrates VR technology, treadmill-assisted movement, and dual-attention tasks to create a dynamic and interactive therapeutic environment. The intervention consists of 3 phases: pre-platform preparation, platform exposure, and post-platform reconsolidation, allowing for structured and progressive trauma processing. Patients engage with self-selected trauma-related images and music, guided by a therapist, to confront distressing memories, reduce avoidance, and foster emotional regulation. The dual-attention task and affect labeling enhance cognitive and emotional integration, while walking promotes a sense of agency and movement through trauma.

Clinical research demonstrates 3MDR’s efficacy in reducing symptoms of PTSD, depression, and anxiety, with high acceptability and low dropout rates among military personnel, veterans, and first responders. Ongoing clinical research suggests 3MDR may be adapted for diverse populations, including civilians and individuals with complex trauma histories.

This manual provides detailed guidance for implementing 3MDR, underscoring the importance of therapist training, ethical considerations, and continued research to optimize its application and expand access to this promising intervention. This manual should be seen as a companion and not a replacement for training.

Main Points

• Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation combines virtual reality, motion-assisted therapy, and personalized trauma cues to treat PTSD, especially in cases resistant to traditional therapies.

• The therapy involves 3 phases—preparation, immersive platform exposure, and post-session reconsolidation—integrating movement, dual-attention tasks, and trauma confrontation.

• Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation has shown effectiveness in reducing PTSD, depression, and anxiety, particularly in military personnel, veterans, and first responders.

• High patient acceptability and low dropout rates make it suitable for diverse populations, including civilians and individuals with complex trauma histories.

• The manual provides guidance on therapist training, ethical practices, and practical application, emphasizing ongoing research and wider accessibility.

Introduction

Trauma-Focused Treatment for Posttraumatic Stress Disorder

Trauma-focused psychotherapies (TFPs), including eye movement desensitization and reprocessing (EMDR), cognitive processing therapy, and prolonged exposure, are efficacious treatments for post-traumatic stress disorder (PTSD) in adults.¹ Each of these therapies contains an element of exposure to trauma cues that is coupled with cognitive restructuring to attain extinction learning and changes in trauma-related cognitions while minimizing avoidance behaviors. Most patients, however, continue to report considerable symptoms post-treatment, including approximately two-thirds of military members and Veterans who retain a diagnosis of PTSD post-treatment.² Some of the difficulties that could account for this include barriers to accessing treatment, significant avoidance, dissociative symptoms, rigid trauma-related beliefs, and self-stigma, which deleteriously affect engagement in psychotherapy. Moral injury can present additional challenges, often complicating treatment and exacerbating resistance.^1,3,4 In addition, current TFPs tend to have high dropout rates (16%-48%) and can result in outcomes comparable to those of non-trauma-focused therapies.^5,6

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation (3MDR) is a psychotherapeutic intervention designed to address common obstacles in traditional TFPs, such as cognitive avoidance and dissociation. 3MDR uses personalized, immersive, virtual reality (VR) supported exposure therapy, where patients walk on a treadmill towards images of self-selected trauma reminders.⁷ 3MDR originated from the high-tech Computer Assisted Rehabilitation Environment (CAREN, Motek Medical B.V., Netherlands⁸) developed for military use to rehabilitate individuals with lower extremity amputations. Instead of using the VR environment for physical rehabilitation, 3MDR was developed for trauma memory processing to help military members recover in terms of mental health.⁹ 3MDR has now been trialed with military members, Veterans, and public safety personnel in several countries including the Netherlands, the United States, the United Kingdom, and Canada.^10-15

Evidence Supporting Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation

Clinical research demonstrates that 3MDR efficiently allows individuals to recover from trauma-related disorders, significantly reducing symptoms of PTSD, major depression, anxiety, and emotional dysregulation, with continued improvements in resilience and psychosocial and general function often seen following treatment.^10,12,14-20 Acceptability of 3MDR is high, as reflected in a pooled dropout rate of 7%-20%,^17,19-21 which is low in comparison to other military populations²² in general (e.g.,⁵).

Studies validating 3MDR’s effectiveness have primarily involved military personnel and veterans in the Netherlands, the United Kingdom, the United States, and Canada, including 3 randomized controlled trials, including addressing treatment-resistant PTSD,^17-19 veterans with PTSD and mild traumatic brain injury,¹⁴ and veterans and first responders with PTSD without prior trauma-focused treatment.²³ Early evidence suggests 3MDR may also benefit those with PTSD with moral injury,¹⁶ increasingly viewed as another form of PTSD. Studies on its effectiveness with civilians are ongoing, including those with occupational trauma and psychological injury in first responders, public safety personnel, and health care professionals.¹⁴ Preliminary work also indicates potential benefits for adolescents with treatment-resistant PTSD,²⁴ older adults, and individuals with trauma from motor vehicle accidents, perinatal and medical procedures, complex grief, and child or adult interpersonal trauma, including sexual trauma, childhood adversities, and interpersonal violence, which may be of potential value in situations of maltreatment (Wen Zeng et al., 2024).²⁵ As 3MDR becomes integrated into public health clinics, continued research and standardized training are required to advance its research and clinical applications.

Aims

This manual establishes the theoretical foundation and detailed description of the standard 3MDR setup and therapeutic protocol (Figures 1 and 2) to ensure consistency in delivery across clinical and research settings. It also presents a practical model of 3MDR that can be tailored for specific conditions or populations.

Figure 1.

3MDR set-up.

Figure 2.

3MDR clinical and research schedule.

Key Components of Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation integrates elements from evidence-based TFPs with personalized trauma cues in a motion-assisted VR environment. Its primary aims are (1) optimal retrieval of trauma memories by engaging patients with self-selected trauma reminders in a VR setting and (2) enhanced memory processing through desensitization, new learning, and memory reconsolidation. This is achieved through multi-sensory input, dual attention tasks, and therapist guidance.

Key components of 3MDR therapy, and the proposed therapeutic processes they are connected to (Figure 3), include:

Figure 3.

Components and aims of 3MDR therapy.

• Walking Toward Trauma Reminders: Walking (defined here as physically moving towards an object) on a treadmill toward self-selected trauma cues facilitates the retrieval and processing of trauma memories.

• Multi-sensory Input: Personalized images and music facilitate immersion and access to memories.

• Immersive VR Environment: The VR technology enhances focused attention on trauma targets and a sense of personal engagement and reduces avoidance.

• Dual Attention Task: Tasks requiring simultaneous attention to 2 stimuli, such as focusing on a traumatic memory while performing lateral eye movements, desensitize distressing memories and promote adaptive reconsolidation.

• Therapist as Coach: The therapist fosters a sense of safety and self-efficacy, provides encouragement and validation, and manages the therapeutic process.

These combined elements, along with emotional, cognitive, and somatosensory experiences that are put into words, help patients regulate while processing trauma, overcome avoidance, enhance access to their trauma memory network (TMN), and integrate the traumatic experience (See Figure 4: 3MDR Treatment Processes and Treatment Effects).

Figure 4.

3MDR treatment processes and treatment effects.

Patient Selection for Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation

Patient selection for 3MDR is important for optimizing treatment outcomes while ensuring patient safety. Inclusion criteria generally favor individuals with treatment-resistant PTSD who are motivated and capable of engaging with both the cognitive and physical demands of the intervention, possess adequate emotional regulation, and have access to a stable support system. Patients with recent-onset PTSD may also be included.

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation is currently delivered within a research setting and is being evaluated for clinical practice. Clinicians select patients based on clinical presentation and study criteria, usually including posttraumatic stress symptoms lasting at least 3 months. Participants must meet the weight and height restrictions of the equipment and be willing to focus on distressing material. Those with medical or physical limitations affecting their ability to walk for 60 minutes at moderate intensity, such as certain musculoskeletal, cardiac, or respiratory conditions, may require further medical evaluation. Jones et al¹¹ have also explored adaptations of 3MDR for those with mobility differences, such as wheelchair users and those with prosthetic devices.

Relative contraindications include conditions such as active suicidality, ongoing psychosis, and other severe psychiatric disorders, which necessitate thorough risk assessment and stabilization before initiating therapy. This ensures that 3MDR is administered to those most likely to benefit while minimizing the likelihood of adverse outcomes during treatment.

Overview of Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation Therapy Phases

It is important to acknowledge that 3MDR utilizes advanced VR hardware and software to create an immersive and interactive therapeutic environment. A medical-grade treadmill and screens are used to create a realistic VR environment (Figure 1). Head Mounted Display may replace screens; however, research is needed to assess how the therapeutic ingredients can still be still maintained within this context. A fall-arrest safety frame and harness ensure patient safety. The specialized VR software generates virtual environments and scenarios, incorporating multi-sensory stimulation (visual and auditory) to personalize and enhance the immersive experience and elicit traumatic memories and emotional responses. The therapist customizes the virtual environment by adjusting images, music, walking speed, dual attention tasks, associative labels, and screen transitions. Subjective units of distress (SUD) scale scores and session notes are also collected through the interface.

Overview of the Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation Protocol and Therapist Script

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation involves 3 distinct phases: (1) a pre-platform preparation phase (up to 3 sessions), (2) a platform exposure phase within the VR environment (typically 6 sessions), and (3) a post-platform reconsolidation phase (2-3 sessions). A typical course of treatment involves weekly 75- to 90-minute sessions, with a goal to complete platform work by week 9. When clinically appropriate, the patient may engage in up to 10 platform exposure sessions. Figure 5 outlines the standard 3MDR structure.

Figure 5.

Overview of 3MDR: phases and platform cycle.

The first 3MDR research study was performed in the Netherlands and approved by the Medical-Ethical Review Committee of Leiden University Medical Center in 2017 (approval no.: P14.325). Since then other centers in the UK, US, and Canada have participated in clinical research.

Phase I: Pre-Platform - Preparation (1-3 Sessions)

During preparation sessions, the therapist builds rapport, conducts an assessment for suitability, and provides education regarding 3MDR. Patients select music and pictures that represent their traumatic experiences, which will be used to anchor the traumatic memory work in phase 2.

Educating About Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation:

The therapist introduces 3MDR to the patient, covering session procedures, the assumed mechanisms of action, potential effects, and the patient’s role in the process. Together, the therapist and patient explore realistic and unrealistic expectations and define specific treatment goals.

Assessing for Treatment Targets:

The therapist guides the patient in identifying key memories or moments in time—referred to as “hotspots”—that have contributed to or intensified the symptoms currently being addressed, such as flashbacks, intrusive thoughts, reliving experiences, or nightmares. Through discussing the most distressing aspects of these memories, triggers, and avoidance behaviors, the therapist helps the patient identify potential images that capture important “stuck points” (in a cognitive or emotional sense) requiring attention in upcoming sessions. Patients are asked to bring a variety of images to the next session that represent these significant trauma-related memories and themes.

Supporting Selection of Pictures and Music:

In the second preparatory session, the therapist and patient select the first 7 images for exposure, ordering them for platform presentation. It is generally advised to start with less distressing images to build confidence and prevent emotional flooding. These images—photographs, artwork, or symbolic representations—can be reordered or replaced at a later time if desensitization or shifting of hotspots occurs. Each image is rated using a SUDs score from 0 (none) to 10 (extreme) regarding the anticipated intensity of emotional response during platform sessions. The therapist asks context questions about each image, observing the patient’s affect and language to assess avoidance, capacity for emotional regulation, existing coping strategies, and therapeutic trust. The sequence of pictures may be guided by either SUDs rankings, identified trauma themes, chronology, or salient trauma narratives. Relaxation or grounding techniques can be practiced or discussed if clinically indicated at this time.

Music is also selected for exposure sessions, with the patient choosing 1 piece associated with the trauma for “warm-up” and another calming and grounding piece for “cool-down” at the end of each exposure session. Warm-up music is often related to the timeframe of the index trauma. The cool-down music is often related to the present day.

Getting Acquainted with Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation Equipment and Process:

Before the first exposure session, the patient is familiarized with the VR environment through a short mock platform session on the treadmill. They ideally bring 2-3 positive or neutral pictures for a “dry run” to experience the 3MDR environment and position of the therapist, accustom themselves to the sequence and process of the 3 main questions, negotiate boundaries on touch, and clarify expectations. It is preferable that the pictures are not explicitly tied to personal experiences, which may unexpectedly provoke negative associations.

Phase II: Platform Sessions—Working Through Trauma (6-10 sessions)

Platform sessions focus on confronting self-selected trauma-related images. During each 90-minute session, the patient walks on a treadmill for 60 minutes in the VR environment, viewing 6-7 self-selected pictures for 5-7 minutes each. The goal is to activate and desensitize cognitive, emotional, and somatosensory components of the trauma memory, enabling narrative processing, new learning, and increased self-efficacy. A dual attention task follows each picture to reduce emotional intensity and enhance desensitization. Walking on the treadmill in the VR environment, supported by a safety harness and the presence of an attuned and responsive therapist, promotes physical and mental engagement, fostering a sense of movement through trauma while feeling grounded. This, in turn, helps the patient review the traumatic content from a different outlook, allowing for a more flexible and broader perspective.

Facilitating Empowerment and Therapeutic Rapport:

In 3MDR therapy, the therapist stands next to (not facing) the treadmill, faces the same display as the patient, and supports the patient as a partner, working together through traumatic experiences. The therapist offers understanding, validation, and encouragement to empower the patient to overcome avoidance and help regulate their emotions from a non-judgmental and accepting therapeutic stance.

The following is a description of the steps in the 3MDR psychotherapeutic process during platform sessions, along with a sample script for 3MDR therapists.

Preparing for the Session:

The therapist and patient make any necessary adjustments to music and images. While the patient is on the platform, the therapist and patient briefly explore any relevant between-session thoughts or experiences that have arisen before starting 3MDR. The therapist may revisit prior discussions to maintain continuity.

Warming Up:

The patient begins the 3MDR session walking on a treadmill in a VR environment with a light-colored (blue) screen and central pathway. The treadmill speed (average speed of 4-4.5 km/h) is adjusted to the patient’s comfort level, and the VR perceived speed is adjusted to match the treadmill speed. Self-selected warm-up music plays for approximately 2-4 minutes to help the patient bring themselves back to the traumatic event. The therapist may remind the patient about the music’s purpose by stating, “The music serves as a mental warm-up that takes you back to the time of the experience.” The music continues until the end of the section as the patient walks. The therapist then cues, “We will now move to the next section with the series of pictures. You will soon see the landscape change, and a tunnel will appear.” The music and blue sky fade, and a darker (black and red) scene appears, revealing a closed door in the distance.

Encouraging Approach Behavior (“Process of Exploration”):

As the patient walks down a virtual path towards the first door in the darkened scene, the therapist helps the patient anticipate the next step: “You are about to enter the first tunnel. After passing through the second door, another tunnel follows, and the picture will appear in the distance. As you continue walking, the picture will come closer and it will seem as if you could step back into the picture.” The picture on the screen grows to full size and eventually becomes static at the end of the tunnel. The therapist then guides the patient through each distressing image and encourages exploration of the image, associated memories, and bodily sensations, thoughts, and feelings that arise.

During each 60-minute platform session, each of the images is displayed for an average of 3-5 minutes, with about 1 to 2 minutes of walking in the VR environment while transitioning to each subsequent image.

Inviting Key Emotional, Cognitive, and Sensorimotor Associations (“Cognitive and Emotional Processing”):

Three key questions guide the 3-5 minute exploration of each image in 3MDR therapy, providing structure and focus during the evolving psychotherapeutic process over subsequent sessions. The questions aim to facilitate deeper processing of the trauma narrative and associated emotional and sensorimotor aspects. A description of and rationale for each question follows (see also Table 1).

Table 1.

Three Questions

Question 1: “What do you SEE in the picture?” Description: The patient is asked to briefly describe the picture, and is redirected if associations about the picture’s meaning, trauma narrative and associated emotional or sensory content arise. The therapist may purposefully direct attention to specific physical details in the image, or items in the picture outside of the patient’s focused attention. Grounding techniques may be used if the patient becomes distressed.	Rationale: This question is about activating the primary sensory visual experience of the image as an object in the here/now (i.e., a picture in front of the person, rather than the trauma itself).
Question 2: “What does the picture TELL you?” Description: The patient briefly describes memories associated with the picture. It is important to probe for a specific memory. Often, the picture is chosen in advance for a hotspot and details are probed for during the 3MDR session.	Rationale: This question allows the person to fully retrieve and maximally engage with the traumatic memory network and access salient parts of the experience.
Question 3: “What do you FEEL in your body NOW?” Description: The patient is asked to identify emotions and associated physical bodily sensations they are experiencing in the present moment on the platform (now). If the patient responds with intellectual descriptions or stories at this stage, the therapist refocuses them on present moment bodily sensations and labels emotions being felt. If labeling emotions is difficult, the therapist may offer emotion words to choose from (e.g., fear or anxiety, anger, shame or guilt, sadness). If the patient reports feeling overwhelmed or severely uncomfortable, the therapist may help by asking for specific, isolated locations where this is felt (e.g., in the chest, the hands) or comment on observed physical cues visible in the patient (e.g., clenched fists, held breath). If this is still overwhelming, or multiple sensory aspects are being experienced, the therapist may make this more manageable by asking the person to choose only 1 physical sensation to describe. A lack of emotion or distress may alternatively signal avoidance or dissociation, or it may mean that the person is not accessing the memory sufficiently. If there is a need to re-engage with the memory or refocus, the therapist may ask the patient to narrate the trauma memory along with its sensory detail (e.g., the temperature, time of day, clothing worn), identify what was stressful, or focus on the photo and any words already placed on the screen (see Affective Labeling for more information). This may help re-activate the trauma memory and stimulate associated emotional and sensory associations to present themselves during therapy. This portion of 3MDR is most amenable to therapeutic personalization. The therapist may tailor their approach to the individual and the situation.	Rationale: The person is asked to connect with the here-and-now physical experience/feeling that arises as the memory is evoked. This experience is often avoided in PTSD.

Question 1: “What do you SEE in the picture?”—This question is about activating the primary sensory visual experience of the image as an object in the here/now as separate from the memory (i.e., a picture in front of the person, rather than the trauma itself).

Question 2: “What does the picture TELL you?”—This allows the person to fully retrieve and maximally engage with the traumatic memory network and access salient parts of the experience.

Question 3: “What do you FEEL in your body NOW?”—The person is asked to connect with the here-and-now physical experience/feeling that arises as the memory is evoked. This experience is often avoided in PTSD.

Processing Trauma:

The therapeutic processes and strategies that go beyond the primary 3 questions are fundamental to 3MDR, helping patients process trauma progressively across sessions. The following sections outline additional core elements of 3MDR that facilitate this evolving trauma processing from one session to the next.

Identifying Emotion-Based Themes:

As 3MDR sessions unfold, recurring themes often emerge, which may be rooted in emotions, beliefs, cognitions, developmental experiences, or interpersonal dynamics. A range of unresolved emotions, such as fear, anger, disgust, sadness, grief, or shame may arise. These may be associated with cognition-based themes that relate to personal judgments or interpretations of events; belief- or value-based themes; moral injury or betrayal; developmental themes tied to specific life stages; impacts on identity; and interpersonal themes reflecting relationships affected by the trauma.

With each session, as therapeutic trust deepens, the therapist encourages the patient to address increasingly distressing aspects of these recurring themes. This progressive exposure enables patients to confront and process core issues in a structured, supportive way that aligns with the 3MDR approach.

Targeting Avoidance:

If avoidance is evident, the therapist makes mental notes regarding aspects of the experience being avoided and prepares to address them in later sessions.

Narrative Processing:

A key feature of 3MDR’s psychotherapeutic process is helping the patient progressively process “hotspots” within each picture through brief exposures within their window of tolerance. In addition to emotional processing, this approach aims to foster deeper understanding and meaning-making. To facilitate narrative processing, the therapist follows the patient’s story, curiously asking the patient to elaborate and reflect on details of the experience. The therapist is especially attentive to ensure that what is emerging is the present moment and to note aspects of the memory where the patient seems to avoid certain details. The therapist might also gently challenge specific cognitions or beliefs through empathic questioning.

Emotions or strong sensations may surface, presenting challenges for the patient to process or manage effectively. 3MDR therapist has the freedom to use their full range of therapeutic skills to help the person explore and experience these aspects of their experience. This can help the person give voice to their experiences and lead to a deeper understanding and expression of the underlying meanings.

Affective Labeling (Continued):

During narration, the therapist and patient work together to choose labels—descriptive words or phrases that encapsulate the emotional, cognitive, or somatosensory aspects of the patient’s experience. Labels are placed on the screen in the foreground of the projected image as they are identified. They capture and organize a particular type of response (e.g., emotion, belief, sensation), theme, or another aspect of a patient’s experience during therapy. In addition to organizing the patient’s experience and facilitating emotional regulation, they allow therapists to track changes and patterns over time and serve as personalized cues to maintain access and engagement with the TMN.

To both facilitate the therapeutic process and determine appropriate labels, the therapist first considers the patient’s responses to the 3 key questions, which will elicit the trauma narrative and emotional and sensory associations. The therapist may support further processing by asking, “Could you say more about this?” The therapist and patient determine the labels together. Once displayed on the screen, the patient is invited to read the labels aloud with as much feeling as is associated with each label, prior to engaging in the dual attention task.

A variable number of potential labels can emerge. At times, an overwhelming set of potential labels arises that span diverse aspects of the experience. The number of labels put on the screen at any one time needs to be limited. Especially early in treatment, it may be useful to focus on successfully navigating 1 specific theme or aspect of the experience to promote a sense of self-efficacy. In addition, focusing on themes of defeat, helplessness, or dissociative responses may be counterproductive in the first sessions. Conversely, someone who actively avoids emotion may benefit from having many evocative labels on the screen to induce an emotional response. The therapist may have to swiftly suggest specific themes to highlight, based on the agreed-upon therapeutic goals, the available material and context, assessment of tolerability, and the nature of the therapeutic relationship.

Engaging in a Dual Attention Task:

Immediately after reading the labels aloud, the patient engages in a 30-second dual-attention task. During this task, the patient simultaneously focuses on their emotional experience while calling out numbers they see appearing on a red ball moving laterally back and forth across the image. This task is designed to facilitate emotional processing.

Initially, the therapist explains: “I’m going to ask you to shift your brain. A part will stay with what you shared, and another part will focus on the red ball with changing numbers. Call out the numbers as the ball moves.” In subsequent sessions: “Are you ready for the ball?” When the ball stops and disappears, the therapist encouragingly comments: “Well done. Now let the memory and picture fade away.”

Rating Subjective Units of Distress:

After the dual attention task, the image and red ball disappear, and the red and black scenery again appear, signaling a break between images. The therapist then asks the patient to rate their current distress level on a scale from 0 to 10 (i.e., SUD scale) by asking, “Please rate, on a scale from 0 to 10, how much distress you are experiencing right now.” “What number were you at before the ball came?” This task should ideally be completed before entering the next tunnel leading to the following picture in the sequence.

Repeating the Cycle:

For each image that is expected to follow, the therapist gently reminds the patient, “As before, you will enter another tunnel and your next picture will appear.” The cycle then repeats with the same 3 questions. Between images, the therapist monitors the walking pace and patient engagement, providing positive words of encouragement and feedback about the work already done. If the patient is distressed, techniques such as diaphragmatic breathing can be used.

Cooling Down—Terminating the Platform Session:

After processing 7 pictures or completing 60 minutes, the patient enters a cool-down period. As the oscillating ball stops and the last picture begins to fade, the therapist provides validating words of assurance by saying, “You’ve done very well; that was your last picture.” The scene then switches back to the calming blue sky with a central pathway. The therapist prepares to play the pre-selected cool-down music and asks the patient, “Are you ready to start your music?” “I’m going to take a step back while still being with you.” The patient walks for about 2-4 minutes as their cool-down music plays. Afterwards, the music is turned down, followed by the slowing of the treadmill to a complete stop. The harness is removed, and the patient and therapist relocate to a sitting area for session reconsolidation.

Platform Session Reconsolidation—Reflecting on Newly Acquired Memories, Experiences, and Skills (“Reflective/Integrative Processing”):

The 60-minute platform exposure is followed by a 15-minute reflection period. This time allows the patient to decompress, receive positive feedback about their hard work on the platform from the therapist, and discuss their observations, including any surprises or new insights. The therapist may ask, “What surprised you during the session?” or “Did you learn anything new?” The therapist may additionally highlight progress being made, discuss relevant themes or issues, and engage in meaning-making. The reconsolidation session also prepares for the next session. Consent for deeper exploration of stuck points or avoided trauma aspects may be obtained, and any potential adjustments to music or images are discussed. For example, a desensitized image might be replaced with a more salient one. The therapist assesses the patient’s current mental state and plans for self-care and safety at home before the next session, as appropriate. This may include a discussion about available supports between sessions, safety planning, or coping skills.

Phase III: Post-Platform—Reconsolidation Sessions (1-3 Sessions)

The post-platform reconsolidation phase offers patients the opportunity to revisit and integrate experiences from across all of the platform (VR exposure) sessions. The first reconsolidation session occurs 1 week after the last platform session, with 1-2 additional reconsolidation sessions occurring over the next 1-3 months.

Stimulating Integration and Post-Session Processing:

Reconsolidation sessions help patients reflect on their progress, consolidate gains, and plan future steps. The focus is on reflective discussion, working through, meaning-making, and incorporating learnings into daily life. The therapist may ask questions such as: “What did you discover or learn during the platform sessions?” Its focus is on positive aspects of integration of traumatic experiences and meaning-making.

Preparing a Post-Traumatic Stress Disorder Management Plan:

These sessions also provide an opportunity for the therapist to ensure a plan for ongoing care after a course of 3MDR treatment. This may include discussing a support plan, identifying triggers for possible PTSD exacerbation, planning future behaviors to handle stressful situations and cope with triggers, isolating tools and skills needed to recover from potential setbacks, and encouraging and generalizing positive cognitions acquired during therapy.

Theoretical Concepts Relevant to Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation

Several theoretical concepts are associated with 3MDR. These include exposure and desensitization, tailored immersion, memory reconsolidation, “touching in” and “touching out,” affect labeling, dual attention task and working memory taxation, embodied cognition, and divergent thinking. A brief discussion of each follows.

Exposure and Desensitization

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation is based on the principles of exposure therapy, where the patient is exposed to traumatic memories or stimuli in a safe manner and with the support of a therapist. Exposure activates the TMN, facilitating desensitization and a decline in the conditioned response, otherwise known as extinction. Extinction is a form of inhibitory learning; the person thus learns that bad things do not always occur when the stimulus is encountered. 3MDR builds on exposure-based therapies by using personalized VR environments.

Tailored Immersion

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation enhances exposure through tailored immersion. Tailored immersion is an important concept in VR, and a key ingredient of 3MDR thought to counter avoidance. In VR and augmented reality, immersion refers to the degree to which a user feels absorbed, engaged, and present in a digital environment. The key principles of immersion are presence, multi-sensory input, interactivity, suspension of disbelief, narrative or goal-oriented structure, and control.²⁶ Presence refers to the feeling of being physically present in a VR environment, even though the user is actually in a different physical location. Multi-sensory input means using multiple senses to create a realistic experience. Interactivity denotes being able to interact with the environment and creating a sense of presence and engagement, which facilitates suspension of disbelief, the person’s ability to accept the digital environment as real. 3MDR utilizes visual, auditory, and proprioceptive senses, as the person interacts with their selected images and music while treadmill walking. Engagement is also enhanced by having a clear narrative or goal-oriented structure. Finally, having a sense of control and the ability to make meaningful choices and decisions can also enhance immersion. In 3MDR, for example, self-selection of images and music may contribute to a sense of control. These elements, along with the person’s real-time associations projected onto the images, customize the experience and increase the specificity of the trauma cues utilized.²⁷ Along with the visual design of the VR environment and physical movement of treadmill walking, the multiple sensory inputs thus result in a highly immersive environment. Personalization creates a stronger connection to and engagement with the treatment process. The intense experience is titrated through collaboration between the therapist and the participant.

Memory Reconsolidation

Memory reconsolidation updates long-term memories with new contextual information. When memory is being recalled, it becomes unstable and is therefore open to change. Introducing new contextual information during this recall can alter the memory before it is restabilized.²⁸ Simply recalling the memory narrative, however, isn’t enough. A mismatch between expectation and what actually happens (known as prediction error) must occur. This “mismatch” can take many forms in 3MDR. Examples may include noticing items in the picture appearing a different size than remembered or receiving reassurance from the therapist, fostering a sense of togetherness when confronting a memory where the patient once felt alone or betrayed. As treadmill walking necessitates postures and movement that may be opposite to the immobility or stuckness that is often experienced during trauma recall, these kinesthetic and proprioceptive cues may additionally provide a sense of self-efficacy, capacity, or sense of “moving forward.” Cognitive shifts or changes in perception during the platform session can alter the meaning of the trauma. These changes are reinforced during reconsolidation periods and post-platform sessions, wherein insights are integrated into the patient’s day-to-day life.

Dual Attention Task and Working Memory Taxation

In 3MDR, a dual attention task is applied that, to some extent, resembles tasks used in EMDR therapy. Participants are asked to simultaneously pay attention to their memory and emotional experience while also following a horizontal ball moving laterally back and forth across the screen in front of them. Studies have found that performing dual attention tasks like lateral eye movements during emotional memory retrieval reduces the vividness and emotionality of these memories. This is thought to occur because both tasks (eye movements and memory retrieval) compete for limited working memory resources,²⁹ making it harder to fully focus on the memory and become overwhelmed by it. This strain, or “taxing,” of the working memory then leads to a reduction in the memory’s vividness and increasing emotional distance.^30,31 In contrast with EMDR, the dual attention task is applied only once after each cycle in 3MDR, and not repeatedly. Supporting evidence for its contribution was found by Roy et al¹⁴ who noted that the dual-task eye movement component of 3MDR enhanced its effectiveness in veterans with comorbid PTSD and mild traumatic brain injury, independent of other therapeutic components.

Pendulating Engagement with Trauma Processing (“Touching In” and “Touching Out”)

“Touching in” and “touching out” of 3MDR refers to the repetitive, alternating process of engaging with and then disengaging from the trauma network. Post-traumatic stress disorder often involves overactivation of the brain’s salience network, which heightens the perception of threat, even in safe situations. This overactivation is associated with dysregulation in the Default Mode Network (responsible for self-referential processing, automated default responses, and memory retrieval) and the Central Executive Network (which controls emotional regulation and higher-order decision-making). Thus, prolonged engagement with trauma-related content may overwhelm regulatory capacities, leading to excessive distress or dissociation that can reinforce a sense of loss of control or incapacity. In addition, these PTSD-related brain changes make it hard to control engagement with traumatic memories. Briefer exposures may reduce overwhelm. Stopping memory retrieval has also been linked to extinction and inhibitory control.³² Learning to alternate between intentionally engaging (“touching in”) and disengaging (“touching out”) from trauma memories may therefore be beneficial during therapy. In 3MDR, the first question, “What do you see in the picture?” helps the patient disengage from evoked memory content and differentiate the past from present by viewing the image as it is, strengthening executive control. Re-engagement occurs with the second question, “What does the picture tell you?”, which invites trauma narrative and associated emotions and sensations. The dual attention task and return to the tunnel entrance after each image provide another cyclical break from trauma processing.

Affect Labeling

Affect labeling is a psychological technique used to help individuals identify and manage their emotions by labeling them. Research has shown that simply labeling emotional responses can reduce distress. When people describe their feelings while experiencing emotionally charged situations, such as looking at negatively valenced images, they tend to feel less emotional intensity than when they do not label their emotions (see³³ for a review). This effect occurs whether people label their own feelings or describe an emotional aspect of an image, and whether they speak, write, or select predefined emotional terms. Studies have shown that adding affect labeling to exposure therapy can lead to a greater reduction in affect compared to exposure conducted without affect labeling.³⁴ Positive emotional tone may increase, while somatosensory processes decrease, which are signs of therapeutic progress. In a study of individuals with spider phobias, for example, labeling emotions during exposure to spider images led to a greater reduction in autonomic activity (measured by skin conductance) after 8 days.³⁵ Labeling promotes self-awareness, reduced emotional intensity, and enhanced coping and communication.³⁶

Embodied Cognition

Embodied cognition is a theory in cognitive science that suggests that the interaction of the body with the environment plays a central role in cognitive processes.³⁷ The theory suggests that mental processes, such as perception, language, and reasoning, are closely tied to physical experiences and bodily sensations. For example, the ability to understand language and make sense of it is influenced by bodily experiences and the gestures used to communicate. Sensory and motor experiences form mental representations of concepts and categories, such as “barking dog” or “empty chair.” Cognitive processes, including metaphor and abstraction, are dynamic and influenced by bodily interactions with the environment. It is suggested that mental representations are also flexible and adaptable. Finally, it is suggested by embodied cognition that actions and experiences are simulated using the same neural circuits that are activated when those actions or experiences are actually engaged in. This allows for mental rehearsal and simulates possible outcomes before taking action.

The use of a treadmill during trauma treatment simulates walking toward feared objects and decreases avoidance of them.^21,38 There can be a sense of having walked towards and “through” the experience, rather than being powerless to confront it. The body can therefore be used as a tool for healing.

Divergent Thinking

Divergent thinking, introduced by psychologist J.P. Guilford in 1956, is a creative thinking process that involves generating multiple ideas or solutions to a problem. Unlike convergent thinking, which seeks a single correct answer, divergent thinking is more open-ended and encourages exploration and possibilities. Research suggests that walking in 3MDR boosts divergent thinking and expression of associative memory.^21,38 Divergent thinking is free-flowing and non-judgmental, making connections between seemingly unrelated ideas, considering alternative perspectives, and challenging assumptions. It is thought to disrupt the rigid, repetitive thought patterns often seen in PTSD, fostering openness and facilitating new insights during 3MDR.

Conclusion

Multi-Modal Motion-Assisted Memory Desensitization and Reconsolidation is an immersive, VR-assisted psychotherapy for treating PTSD and other trauma-related disorders. Developed in the Netherlands, 3MDR is being continuously researched, refined, and delivered globally by the 3MDR International Consortium. This brief manual provides an introduction to the theory underlying 3MDR and describes its setup and therapeutic process. It is important to note that while reviewing this manual is essential for 3MDR delivery, it is not sufficient. This manual should be seen as a companion and not a replacement for training. Clinicians must undergo training to offer 3MDR. Information about 3MDR training is available from the first author.

Funding Statement

Netherlands: ZonMw; National Care for Veterans; Dutch Ministry of Defense; Nypels Tans PTSD Fund; Karel Doorman Fund; Canada: HiMARC, the Royal Canadian Legion AB/NWT Command; Government of Alberta; Glenrose Rehabilitation Hospital Foundation, First Response to Fashion; Government of Canada Innovation for Defence Excellence and Security (IDEaS) Grant, Canadian Armed Forces; Alberta Health Services, Veterans Affairs Canada; United States: U.S. Bureau of Medicine and Surgery.

Data Availability Statement:

The data that support the findings of this study are available upon request from the corresponding author.