Digital Biofeedback for Combat Veterans Diagnosed With PTSD

Evaluating the Efficacy of the "Mental Gym®" Biofeedback-Based Intervention for Combat Veterans Diagnosed With PTSD: A Randomized Controlled Trial

This randomized controlled trial (RCT) will evaluate the effectiveness of a digital biofeedback-based intervention ("Mental Gym®") designed to reduce Posttraumatic Stress Disorder (PTSD) symptoms and improve mental health. The intervention combines daily HRV biofeedback exercises using a wearable device (Garmin watch), a dedicated mobile application, and weekly group guidance sessions. A delayed-intervention control group design will be used. To account for expected attrition and ensure a final sample of 60 participants, approximately 80 subjects will be recruited. Physiological and self-report data will be collected pre- and post-intervention, weekly during the intervention, and at follow-ups (3 months post-intervention). The study population consists of combat veterans diagnosed with PTSD.

Study Overview

• Status: Recruiting
• Conditions: PTSD - Post Traumatic Stress Disorder
• Intervention / Treatment: Behavioral: Mental Gym® Biofeedback System

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Israel
  • Jerusalem, Israel
    • Recruiting
    • NeuroBrave LTD - Remote Site
    • Contact: Inbal Dorfman; Phone Number: +972-547858149; Email: inbal.dorfman@neurobrave.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Sex: Male
• Age: 18 Years and older.
• Diagnosis: Clinical diagnosis of Posttraumatic Stress Disorder (PTSD) with mild to moderate-severe symptom intensity.
• Symptom Severity: A PCL-5 total score of up to 60 at screening.
• Traumatic Event: PTSD diagnosis based on a traumatic event that occurred in the year 2000 or later.
• Service Eligibility: Eligibility for Ministry of Defense (MOD) rehabilitation services.
• Technical Proficiency: Ability to use a smartphone and a wearable device.

Exclusion Criteria:

• High Symptom Severity: PTSD symptom severity exceeding the moderate-severe range (PCL-5 score > 60) or requiring more intensive clinical intervention.
• Psychiatric Stability: Acute psychiatric instability, including active suicidal ideation or psychosis.
• Medication: Current use of Olanzapine (Zyprexa) or Quetiapine (Seroquel).
• Sleep Disturbances: Severe sleep impairment (score > 7 on the The Insomnia Severity Index).
• Functional Impairment: Severe impairment in concentration or cognitive processing that precludes the use of digital biofeedback tools.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Mental Gym® Immediate Intervention	Behavioral: Mental Gym® Biofeedback System; The intervention is an 8-week hybrid program designed to reduce symptoms of PTSD and improve mental health. The program includes weekly online sessions (via Zoom) with a specialist psychologist experienced in biofeedback and trauma therapy. These sessions guide participants through the program, provide education on trauma and autonomic system and explain the biofeedback exercises. In addition to the weekly group sessions, participants engage in a dailyself-practice delivered through the NeuroBrave Sense mobile application, utilizing the provided wearable device ( Garmin watch) for real time biofeedback practices. Supplementary mental practice assignments are also delivered to participants via WhatsApp.
No Intervention: Delayed Intervention (Waitlist Control plus Garmin Watch); Participants in this arm will initially serve as a no-intervention control group for a period of 8 weeks, during which they will continue with their Treatment as Usual (TAU). Following this 8-week period, they will receive the full 'Mental Gym®' intervention, identical to the experimental group, including the mobile application, and weekly sessions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in PTSD Symptom Severity (PCL-5 Total Score)	The primary outcome is the change in the total score of the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5). The PCL-5 is a 20-item self-report measure; items are rated on a 0-4 point scale. Total score ranges from 0 to 80, where higher scores indicate greater symptom severity. PCL scores are expected to reduce in the intervention but not in the control groups.	Baseline (Week 0) and Post-Intervention (Week 8).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Long term retention of Treatment Effects in the Intervention Group	To assess long term improvement trajectories and retention, we will combine all intervention arm participants and conduct longitudinal within subjects analysis on primary and secondary change measures at post intervention, as well as 1.5-month Follow-up (Week 14), and 3-month Follow-up (Week 20). This analysis will also be used to identify subpopulations within our sample for whom the treatment was more or less beneficial. We expect the clinical improvement to remain significant through the follow up time points.	Baseline (Week 0), Post-Intervention (Week 8), 1.5-month Follow-up (Week 14), and 3-month Follow-up (Week 20)
Change in Autonomic Regulation (Resting HRV)	change in resting heart rate variability (HRV) will be used as a physiological marker of autonomic regulation. HRV will be derived from inter-beat interval data collected during 5 min resting conditions during the first and the last group sessions using a wearable device and summarised using standard time-domain metrics (e.g., RMSSD). Higher HRV values and lower heart rate (HR) reflect greater parasympathetic activity and improved autonomic regulation. Resting HRV scores are expected to increase and resting HR to decrease in the intervention but not in the control groups.	Baseline (Week 0) and Post-Intervention (Week 8)
Change in Generalized Anxiety Symptoms (GAD-7)	Generalized anxiety symptoms will be assessed using the Generalized Anxiety Disorder 7-item questionnaire (GAD-7), a validated self-report measure of anxiety severity. Total scores range from 0 to 21, with higher scores indicating greater anxiety symptoms. Generalized anxiety symptoms are expected to reduce in the intervention but not in the control groups.	Baseline (Week 0) and Post-Intervention (Week 8)
Change in Depressive Symptoms (PHQ-9)	Depressive symptoms will be measured using the Patient Health Questionnaire-9 (PHQ-9), a validated self-report instrument assessing the severity of depressive symptoms over the past two weeks. Total scores range from 0 to 27, with higher scores indicating greater depressive symptom severity. Depressive symptoms are expected to reduce in the intervention but not in the control groups	Baseline (Week 0), Post-Intervention (Week 8)
Change in Psychological Resilience (CD-RISC-10)	Psychological resilience will be assessed using the 10-item Connor-Davidson Resilience Scale (CD-RISC-10), a validated self-report measure of perceived resilience and stress coping capacity. Total scores range from 0 to 40, with higher scores indicating greater resilience.Psychological resilience is expected to reduce in the intervention but not in the control groups.	Baseline (Week 0), Post-Intervention (Week 8)
Change in Sleep Quality (ISI)	Sleep quality will be measured using the Insomnia Severity Index (ISI), a validated self-report questionnaire assessing subjective sleep quality. The total SQS score will be used, with higher scores indicating poorer sleep quality. Sleep quality is expected to reduce in the intervention but not in the control groups.	Baseline (Week 0), Post-Intervention (Week 8)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weekly Change in PTSD Symptom Severity (PCL-6)	The PTSD Checklist - 6-item version (PCL-6) is a validated self-report screening tool for Post-Traumatic Stress Disorder. It assesses symptoms such as intrusive thoughts, avoidance, and hyperarousal. Total scores range from 6 to 30, with higher scores indicate greater symptom severity. A decrease in scores over time represents clinical improvement.	Baseline, and weekly through Week 8
Weekly Change in Psychological Wellbeing (ORS)	The Outcome Rating Scale (ORS) is a 4-item visual analogue scale designed to measure change in three areas of client functioning: individual (personal well-being), interpersonal (family/close relationships), and social (work/school/friendships), as well as overall well-being. Total scores range from 0 to 40, with higher scores indicate better psychological wellbeing and functioning. An increase in scores over time represents improvement.	Baseline, and weekly through Week 8

Collaborators and Investigators

• Sponsor: NeuroBrave ltd.

Publications and helpful links

General Publications

• Connor KM, Davidson JR. Development of a new resilience scale: the Connor-Davidson Resilience Scale (CD-RISC). Depress Anxiety. 2003;18(2):76-82. doi: 10.1002/da.10113.
• Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001 Sep;16(9):606-13. doi: 10.1046/j.1525-1497.2001.016009606.x.
• Spitzer RL, Kroenke K, Williams JB, Lowe B. A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med. 2006 May 22;166(10):1092-7. doi: 10.1001/archinte.166.10.1092.
• Blevins CA, Weathers FW, Davis MT, Witte TK, Domino JL. The Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5): Development and Initial Psychometric Evaluation. J Trauma Stress. 2015 Dec;28(6):489-98. doi: 10.1002/jts.22059. Epub 2015 Nov 25.
• Tan G, Dao TK, Farmer L, Sutherland RJ, Gevirtz R. Heart rate variability (HRV) and posttraumatic stress disorder (PTSD): a pilot study. Appl Psychophysiol Biofeedback. 2011 Mar;36(1):27-35. doi: 10.1007/s10484-010-9141-y.
• Lang AJ, Stein MB. An abbreviated PTSD checklist for use as a screening instrument in primary care. Behav Res Ther. 2005 May;43(5):585-94. doi: 10.1016/j.brat.2004.04.005.
• Cuyler RN, Katdare R, Thomas S, Telch MJ. Real-world outcomes of an innovative digital therapeutic for treatment of panic disorder and PTSD: A 1,500 patient effectiveness study. Front Digit Health. 2022 Nov 17;4:976001. doi: 10.3389/fdgth.2022.976001. eCollection 2022.
• Schuman DL, Lawrence KA, Boggero I, Naegele P, Ginsberg JP, Casto A, Moser DK. A Pilot Study of a Three-Session Heart Rate Variability Biofeedback Intervention for Veterans with Posttraumatic Stress Disorder. Appl Psychophysiol Biofeedback. 2023 Mar;48(1):51-65. doi: 10.1007/s10484-022-09565-z. Epub 2022 Nov 4.
• Rosaura Polak A, Witteveen AB, Denys D, Olff M. Breathing biofeedback as an adjunct to exposure in cognitive behavioral therapy hastens the reduction of PTSD symptoms: a pilot study. Appl Psychophysiol Biofeedback. 2015 Mar;40(1):25-31. doi: 10.1007/s10484-015-9268-y.
• Morin CM,Belleville G,Bélanger L,Ivers H

Study record dates

Study Major Dates

• Study Start (Actual): September 15, 2025
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): September 30, 2026

Study Registration Dates

• First Submitted: March 5, 2026
• First Submitted That Met QC Criteria: March 5, 2026
• First Posted (Actual): March 10, 2026

Study Record Updates

• Last Update Posted (Actual): March 10, 2026
• Last Update Submitted That Met QC Criteria: March 5, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Trauma and Stressor Related Disorders; Mental Disorders; Stress Disorders, Traumatic; Combat Disorders
• Other Study ID Numbers: P_2025176

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No