Posttraumatic Stress Disorder (PTSD)TSTVNCT07891559
Trauma Suppression Training for Veterans
A study testing Web-based Think/No-Think retrieval-suppression training in people with Posttraumatic Stress Disorder (PTSD), run by Palo Alto Veterans Institute for Research at 1 site in United States.
Trial 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). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Posttraumatic Stress Disorder (PTSD)
- What is being tested?
- Web-based Think/No-Think retrieval-suppression training
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 11 participants
- Where
- 1 siteUnited States
- Study dates
- 5 Nov 2025to 8 Jul 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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.
Show all 10Show fewer
- 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.
Trial locations and contacts
1 site in 1 country.
United States1 site
VA Palo Alto Medical Center
Palo Alto, California, 94304
About this study
Official title: Trauma Suppression Training in Veterans: A Feasibility Study
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.
Read the detailed description
This single-site feasibility study adapted a web-based Think/No-Think retrieval-suppression training program, previously tested in the general population, for veterans with PTSD. At an introductory session, participants gave consent, completed baseline questionnaires, and received instructions for generating 40 personally significant events (20 negative, 20 positive), each with a cue (Hint) word and a key-detail (Response) word. After stimulus preparation (1 to 3 days), participants completed three consecutive training days. On Day 1 they rated each event and learned the 40 cue-detail pairs. On each training day they completed four runs of the Training Task: on No-Think trials (negative events) they recognized the event but stopped it from coming to mind without substituting other thoughts; on Think trials (positive events) they recalled the event and imagined it vividly. Untrained events of each valence served as baseline items. On Day 3 participants completed a cued-recall test, re-rated event vividness and affect, and completed post-training questionnaires.
The protocol was revised during the study through IRB-approved amendments. Initially, participants were randomly assigned to one of four instruction conditions that differed only in the suppression strategy offered (flexible strategy, visual focus, breath focus, or heart-centered visualization), and sessions were held in person. From December 2025, all sessions could be held remotely and all participants received the flexible-strategy instruction, with the structured strategies suggested as optional aids. From February 2026, positive and negative events could be drawn from the past, present, or future rather than only past negative and future positive events.
- Conditions
- Posttraumatic Stress Disorder (PTSD)
- Being tested
- Web-based Think/No-Think retrieval-suppression training
- Keywords
- intrusive memories, thought suppression, retrieval suppression, Think/No-Think, memory control, veterans, feasibility, web-based intervention, inhibitory control, cognitive training
- Medical subject headings
- Stress Disorders, Post-Traumatic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Web-based Think/No-Think retrieval-suppression trainingBehavioural
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.
| Study group | Role | What they receive |
|---|---|---|
| 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). Receives: Behavioral: Web-based Think/No-Think retrieval-suppression training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Recruitment
Number of eligible veterans enrolled (consented) during the recruitment period, against the target of 20 completers.
Measured: Recruitment period (November 2025 to July 2026)
Retention
Percentage of consented participants who complete all study sessions.
Measured: From consent through Training Day 3 (about 5 days)
Protocol adherence
Percentage of participants who begin training and complete all three training days.
Measured: 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.
Measured: 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.
Measured: From stimulus preparation through Training Day 3 (about 5 days)
Adverse events
Number of participants with serious adverse events.
Measured: 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).
Measured: 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).
Measured: 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.
Measured: Training Day 3
Secondary outcomes (8)
Warwick-Edinburgh Mental Well-being Scale (WEMWBS)
Change in total score (range 14 to 70; higher scores indicate better well-being).
Measured: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Positive and Negative Affect Schedule (PANAS)
Change in positive affect and negative affect subscale scores (10 items each, rated 1 to 5; each subscale range 10 to 50). Higher positive-affect scores indicate a better outcome; higher negative-affect scores indicate a worse outcome.
Measured: Baseline (introductory session) and end of Training Day 3 (about 5 days)
State-Trait Anxiety Inventory, state form (STAI-S)
Change in total score (range 20 to 80; higher scores indicate more anxiety).
Measured: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Penn State Worry Questionnaire-Past Day (PSWQ-PD)
Change in total score (range 0 to 60; higher scores indicate more worry).
Measured: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Beck Depression Inventory-II (BDI-II)
Change in total score (20-item version without the suicidal-thoughts item; range 0 to 60; higher scores indicate more depressive symptoms).
Measured: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Event vividness ratings
Change in vividness ratings (1 to 5) of trained versus untrained events, from Training Day 1 to Training Day 3.
Measured: Training Day 1 and Training Day 3
Event affect ratings
Change in distress (negative events) or joy (positive events) ratings (1 to 5), from Training Day 1 to Training Day 3.
Measured: Training Day 1 and Training Day 3
Cued recall
Percentage of Response Words recalled for trained versus untrained events on Training Day 3.
Measured: Training Day 3
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Oct 2026
- Study start5 Nov 2025
- Primary completion8 Jul 2026
- Study completion8 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Posttraumatic Stress Disorder (PTSD)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- 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.
- Masking
- None (open label)
- Enrolment
- 11 participants (actual)
Sponsor and investigators
- Lead sponsor
- Palo Alto Veterans Institute for Research
- Sponsor type
- University, hospital or other
- Collaborators
- Stanford University
- Responsible party
- Principal investigator, Peter Bayley, Palo Alto Veterans Institute for Research
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07891559
- Sponsor's protocol ID
- 78220
- Other IDs
- RDIS No. BAY0012
- Acronym
- TSTV
- Status last verified
- Oct 2026
- First submitted
- 9 Oct 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: De-identified data may be made available by the investigators on reasonable request, subject to VA data-sharing policy.
Publications
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.
PubMed 37729415
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Trauma Suppression Training in Veterans: A Feasibility Study
- ClinicalTrials.gov ID
- NCT07891559
- Acronym / sponsor ID
- TSTV / 78220
- Conditions
- Posttraumatic Stress Disorder (PTSD)
- Keywords
- intrusive memories, thought suppression, retrieval suppression, Think/No-Think, memory control, veterans, feasibility, web-based intervention
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 11 participants (actual)
- Lead sponsor
- Palo Alto Veterans Institute for ResearchUniversity, hospital or other
- Collaborators
- Stanford University
- Study start
- 5 Nov 2025 (actual)
- Primary completion
- 8 Jul 2026 (actual)
- Study completion
- 8 Jul 2026 (actual)
- First posted
- 23 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This single-site feasibility study adapted a web-based Think/No-Think retrieval-suppression training program, previously tested in the general population, for veterans with PTSD. At an introductory session, participants gave consent, completed baseline questionnaires, and received instructions for generating 40 personally significant events (20 negative, 20 positive), each with a cue (Hint) word and a key-detail (Response) word. After stimulus preparation (1 to 3 days), participants completed three consecutive training days. On Day 1 they rated each event and learned the 40 cue-detail pairs. On each training day they completed four runs of the Training Task: on No-Think trials (negative events) they recognized the event but stopped it from coming to mind without substituting other thoughts; on Think trials (positive events) they recalled the event and imagined it vividly. Untrained events of each valence served as baseline items. On Day 3 participants completed a cued-recall test, re-rated event vividness and affect, and completed post-training questionnaires.
The protocol was revised during the study through IRB-approved amendments. Initially, participants were randomly assigned to one of four instruction conditions that differed only in the suppression strategy offered (flexible strategy, visual focus, breath focus, or heart-centered visualization), and sessions were held in person. From December 2025, all sessions could be held remotely and all participants received the flexible-strategy instruction, with the structured strategies suggested as optional aids. From February 2026, positive and negative events could be drawn from the past, present, or future rather than only past negative and future positive events.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- 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.
| Arm | Type | Receives |
|---|---|---|
| Think/No-Think suppression training | Experimental | Behavioral: Web-based Think/No-Think retrieval-suppression trainingParticipants 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). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 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
Key exclusion criteria (10 listed)
- 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).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Web-based Think/No-Think retrieval-suppression trainingEach 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. | Behavioural | Think/No-Think suppression training |
Primary outcome
Recruitment
Time frame: Recruitment period (November 2025 to July 2026)
Number of eligible veterans enrolled (consented) during the recruitment period, against the target of 20 completers.
Retention
Time frame: From consent through Training Day 3 (about 5 days)
Percentage of consented participants who complete all study sessions.
Protocol adherence
Time frame: Training Days 1 to 3
Percentage of participants who begin training and complete all three training days.
Number of participants rating the suppression strategy as useful outside the laboratory
Time frame: End of Training Day 3
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.
Number of completers whose training was delivered on the protocol-specified schedule
Time frame: From stimulus preparation through Training Day 3 (about 5 days)
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.
Adverse events
Time frame: From consent through Training Day 3
Number of participants with serious adverse events.
Number of participants likely to re-use the suppression strategy, assessed by a 5-point rating item
Time frame: End of Training Day 3
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).
Self-rated effectiveness at stopping thoughts about upsetting events, assessed by a 5-point rating item
Time frame: End of Training Day 3
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).
Number of completers confirming the suppression-strategy instruction they were assigned, assessed by a post-training yes/no item
Time frame: Training Day 3
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.
8 secondary outcomes
Warwick-Edinburgh Mental Well-being Scale (WEMWBS)
Time frame: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Positive and Negative Affect Schedule (PANAS)
Time frame: Baseline (introductory session) and end of Training Day 3 (about 5 days)
State-Trait Anxiety Inventory, state form (STAI-S)
Time frame: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Penn State Worry Questionnaire-Past Day (PSWQ-PD)
Time frame: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Beck Depression Inventory-II (BDI-II)
Time frame: Baseline (introductory session) and end of Training Day 3 (about 5 days)
Event vividness ratings
Time frame: Training Day 1 and Training Day 3
Event affect ratings
Time frame: Training Day 1 and Training Day 3
Cued recall
Time frame: Training Day 3
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2026.
- Background: PubMed 37729415Mamat 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.
- Individual participant dataSharing planned: Undecided. De-identified data may be made available by the investigators on reasonable request, subject to VA data-sharing policy.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Web-based Think/No-Think retrieval-suppression training in people with Posttraumatic Stress Disorder (PTSD), run by Palo Alto Veterans Institute for Research at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Recruitment (time frame: Recruitment period (November 2025 to July 2026)). The study lists 9 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07891559, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Oct 2026.