Trauma Suppression Training for Veterans

NCT07891559 | Completed

• 2 other identifiers: 78220RDIS No. BAY0012
• Study Type: interventional
• Target: 11
• Locations: 1 country
• Sites: 1

Brief Summary

Intrusive memories of trauma are a core and often persistent symptom of posttraumatic stress disorder (PTSD). This study tested whether veterans with PTSD could take part in a computer-based training program that teaches people to stop unwanted memories from coming to mind (the Think/No-Think procedure). Veterans listed personally significant negative and positive events, learned a cue word for each, and then practiced suppressing the negative events and vividly recalling the positive ones over three consecutive days, in person or remotely. The study measured whether veterans could be recruited and retained, whether they completed the training, how acceptable they found it, and whether it was safe. It also explored changes in anxiety, worry, mood, wellbeing, and depressive symptoms, and in how vivid and distressing the trained memories were.

Conditions

Posttraumatic Stress Disorder (PTSD)

Keywords

intrusive memories; thought suppression; retrieval suppression; Think/No-Think; memory control; veterans; feasibility; web-based intervention; inhibitory control; cognitive training

Outcome Measures

Primary Outcomes (9)

• Recruitment

  Number of eligible veterans enrolled (consented) during the recruitment period, against the target of 20 completers.

  Recruitment period (November 2025 to July 2026)

• Retention

  Percentage of consented participants who complete all study sessions.

  From consent through Training Day 3 (about 5 days)

• Protocol adherence

  Percentage of participants who begin training and complete all three training days.

  Training Days 1 to 3

• Number of participants rating the suppression strategy as useful outside the laboratory

  Single post-training yes/no item: "Do you think that the suppression strategy you learned through the course of this training is useful or helpful to use outside the lab in your own life?" Reported as the number and percentage of participants answering Yes; a higher percentage indicates greater acceptability.

  End of Training Day 3

• Number of completers whose training was delivered on the protocol-specified schedule

  Delivery was recorded as per protocol when stimulus preparation was followed by three training days on consecutive days, as specified in the protocol. Reported as the number and percentage of completers; a higher percentage indicates greater fidelity of delivery.

  From stimulus preparation through Training Day 3 (about 5 days)

• Adverse events

  Number of participants with serious adverse events.

  From consent through Training Day 3

• Number of participants likely to re-use the suppression strategy, assessed by a 5-point rating item

  Single post-training item: "How likely are you to re-use the suppression strategy you learned to decrease your anxiety or thoughts about the negative events in your life?" Rated from 1 (Very unlikely) to 5 (Very likely); minimum 1, maximum 5; higher scores indicate greater likelihood of re-use (a better outcome). Reported as the number and percentage of participants rating Likely (4) or Very likely (5).

  End of Training Day 3

• Self-rated effectiveness at stopping thoughts about upsetting events, assessed by a 5-point rating item

  Participants rated how effectively they could stop thoughts about their upsetting events at the beginning of training (Training Day 1, rated retrospectively) and at the end of training (Training Day 3). Each rating ranges from 1 (Not at all effective) to 5 (Extremely effective); higher scores indicate better self-rated effectiveness (a better outcome).

  End of Training Day 3

• Number of completers confirming the suppression-strategy instruction they were assigned, assessed by a post-training yes/no item

  After training, participants were shown the strategy instruction for their assigned condition and asked to confirm (Yes/No) that it was the strategy they had practiced. Reported as the number and percentage answering Yes; a higher percentage indicates more accurate delivery of the assigned instruction.

  Training Day 3

Secondary Outcomes (8)

• Warwick-Edinburgh Mental Well-being Scale (WEMWBS)

  Baseline (introductory session) and end of Training Day 3 (about 5 days)

• Positive and Negative Affect Schedule (PANAS)

  Baseline (introductory session) and end of Training Day 3 (about 5 days)

• State-Trait Anxiety Inventory, state form (STAI-S)

  Baseline (introductory session) and end of Training Day 3 (about 5 days)

• Penn State Worry Questionnaire-Past Day (PSWQ-PD)

  Baseline (introductory session) and end of Training Day 3 (about 5 days)

• Beck Depression Inventory-II (BDI-II)

  Baseline (introductory session) and end of Training Day 3 (about 5 days)

Other Outcomes (2)

• PTSD Checklist for DSM-5 (PCL-5) total score

  Training Day 3

• Cambridge Selective Forgetting Inventory (CSFI)

  Baseline (introductory session)

Study Arms (1)

Think/No-Think suppression training

EXPERIMENTAL

Participants generate 40 personally significant events, learn cue-detail word pairs, and complete three consecutive days of web-based Think/No-Think training (No-Think trials for negative events, Think trials for positive events).

Behavioral: Web-based Think/No-Think retrieval-suppression training

Interventions

Web-based Think/No-Think retrieval-suppression training BEHAVIORAL

Each training day comprises four runs in which 16 trained events (8 Think, 8 No-Think) are each presented three times (192 trials per day); each cue is shown for 5 seconds. On No-Think trials, participants keep their attention on the cue while preventing the associated memory from coming to mind, without substituting other thoughts.

Think/No-Think suppression training

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 years or older.
• Veteran who served in active combat or in a combat zone.
• Current PTSD, defined by a PTSD Checklist for DSM-5 (PCL-5) score above 38 at screening or a self-reported prior PTSD diagnosis

You may not qualify if:

• Participation in another concurrent clinical trial.
• Past participation in a research study involving the Think/No-Think task.
• No access to a laptop computer for all training days, or no experience using Microsoft Excel or Google Sheets.
• Color blindness; dyslexia or other reading disability; inability to read and communicate in English.
• History of psychotic episodes; neurodegenerative disorder (e.g., dementia, Parkinson's disease).
• Current or recent (within 60 days) suicidal or homicidal intent at screening.
• Schizophrenia, bipolar I disorder, or psychosis for any reason within the prior six months.
• Substance dependence (other than nicotine) within the prior 30 days.
• Poorly controlled seizure disorder.
• Psychotropic medication started within 8 weeks before screening.

Sponsors & Collaborators

• Palo Alto Veterans Institute for Research: lead
• Stanford University: collaborator

Study Sites (1)

VA Palo Alto Medical Center

Palo Alto, California, 94304, United States

Location

Related Publications (1)

• Mamat Z, Anderson MC. Improving mental health by training the suppression of unwanted thoughts. Sci Adv. 2023 Sep 22;9(38):eadh5292. doi: 10.1126/sciadv.adh5292. Epub 2023 Sep 20.

  PMID: 37729415 BACKGROUND

MeSH Terms

Conditions

Stress Disorders, Post-Traumatic

Condition Hierarchy (Ancestors)

Stress Disorders, Traumatic; Trauma and Stressor Related Disorders; Mental Disorders

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of Research, War Related Illness and Injury Study Center

Model Details: All participants received web-based Think/No-Think training. In the first phase, participants were randomly assigned to one of four suppression-strategy instruction conditions; after two participants, this was replaced by a single flexible-strategy condition.

Study Record Dates

• First Submitted: October 9, 2026
• First Posted: October 23, 2026
• Study Start: November 5, 2025
• Primary Completion: July 8, 2026
• Study Completion: July 8, 2026
• Last Updated: October 23, 2026

Record last verified: 2026-10

Locations

US (1)