Visuospatial game task after trauma (Tetris intervention)

1. Introduction

Version followed: the Holmes / Iyadurai group's "brief imagery-competing task intervention" in its guided, multi-memory form (one guided session, then self-guided use, plus optional further guided sessions), as published for long-standing intrusions in Iceland (Hardarson et al., 2024) and NHS intensive-care staff (Iyadurai et al., 2023; GAINS-2 protocol). Three variants are also described: the early single-session version given soon after trauma in emergency departments (Iyadurai et al., 2018; Kanstrup et al., 2021), the adjunct version given after imaginal-exposure sessions in inpatient trauma-focused CBT (Badawi et al., 2021), and a cube mental-rotation variant (Kessler, ISRCTN52555566).

What it is: a brief, low-intensity cognitive task targeted at one symptom, intrusive memories (sensory, image-based memories of a trauma that come to mind unbidden). It is not a full trauma therapy and does not process the trauma narrative. The client briefly brings one specific intrusive memory to mind (a "memory reminder cue"), without describing it, then plays the computer game Tetris for about 20 minutes while deliberately using mental rotation (imagining how upcoming blocks can be turned to fit). Each intrusive memory is targeted separately, and intrusions are counted in a diary to see whether each one becomes less frequent. [source: Hardarson et al., 2024; GAINS-2 protocol; Kanstrup et al., 2021 abstract]

Core idea of change (the developers' hypothesis, not established fact): intrusive memories are held as vivid visual imagery. A memory that has just been brought back to mind is thought to be open to modification for a period, and an engaging visuospatial task done in that window is thought to compete for the same limited visuospatial/imagery resources, so the memory is re-stored in a form that intrudes less often. The developers now call it an "imagery-competing task". [source: trial titles and abstracts, Iyadurai et al., 2023; Kanstrup et al., 2021] [uncertain: the detailed mechanism papers (consolidation/reconsolidation accounts) are not drawn on; this summary is a paraphrase of the general rationale]

Developers: Emily A. Holmes (Uppsala University and Oxford) and Lalitha Iyadurai (Oxford; P1vital), with Michael Kanstrup, Laura Singh, Beau Gamble and colleagues. Henrik Kessler's Bochum group has tested related versions in Germany; Badawi, Steel and colleagues in Australia. [source: citations of the records] Tetris is a registered trademark; the trials used Tetris on a handheld or tablet, the free browser version at tetris.com (Iceland), or a licensed version inside the i-spero® digital platform (GAINS-2). [source: Hardarson et al., 2024; GAINS-2 protocol; Badawi et al., 2021]

2. Framework

The intervention is used in three ways. Pick one before starting.

A. Guided multi-memory version (main version followed; for existing intrusions, weeks to decades after trauma) [source: Hardarson et al., 2024; GAINS-2 protocol; Iyadurai et al., 2023 abstract]

Eligibility used in the trials: adults with at least one DSM-5 Criterion A traumatic event and current intrusive memories of it. Minimum frequency varied by trial: at least 2 intrusions in the past week (Iceland), at least 3 in the past week and in the run-in week (GAINS-2), at least 5 a week for 2 weeks (Kessler). Exclusions used: current psychotic disorder or psychotic symptoms; current manic episode; acute suicidality; severe self-harm needing medical care in the past 6 months; problematic substance use (Kessler, Badawi); and, in Kessler's trial only, ongoing trauma-exposure therapy. GAINS-2 did not exclude people having other PTSD treatment. [source: Hardarson et al., 2024; GAINS-2 protocol; ISRCTN52555566; Badawi et al., 2021]

Criteria for moving from one target memory to the next: the Iceland study retargeted the same intrusion at the next session if it persisted, or chose a different one the client wanted to reduce. No published rule for when a memory counts as finished was found [uncertain]. A workable rule [synthesis]: move on when the target intrusion has occurred no more than once in the past week, or when the client judges it no longer a problem; keep the same target for two to three rounds before concluding it is not responding.

B. Early single-session version (hours to days after a trauma) [source: Iyadurai et al., 2018 record; Kanstrup et al., 2021 abstract]: one session in the hospital emergency department after a traumatic event (Kanstrup: within 72 hours of arrival), consisting of the memory reminder cue plus Tetris with mental-rotation instructions, then an intrusion diary for a week. [uncertain: the 2018 trial's exact time window and trauma type (reported in secondary coverage as within 6 hours of a motor vehicle accident) are not confirmed from the full text]

C. Adjunct to imaginal exposure in trauma-focused CBT [source: Badawi et al., 2021]: after a therapy session that included at least 15 minutes of imaginal exposure (which serves as the memory reactivation), the client plays mental-rotation Tetris for 12 minutes on a tablet the clinician hands over at the end of the session. This was done for the first three such sessions in an inpatient programme of 3–4 sessions a week over 3–5 weeks.

3. Guiding principles

• Target the symptom, not the story. The unit of work is a single intrusive memory, not the trauma narrative. Practical meaning: you do not need, and should not ask for, a detailed account. [source: Hardarson et al., 2024; GAINS-2 protocol]
• Brief reminder, no detailed recall. Practical meaning: the client brings the image to mind "in their mind's eye" for a moment, or writes a few words, and then moves straight to the game. [source: Hardarson et al., 2024; GAINS-2 protocol]
• One memory at a time. Practical meaning: each intrusion is labelled and targeted on its own; reductions are expected mainly in the targeted memory. [source: Hardarson et al., 2024] [uncertain: target-specific effects are reported in other Holmes-group papers not drawn on here]
• Pair the reminder with the task. Practical meaning: the game follows straight after the reminder, in the same sitting; do not let a gap open up for talking about the memory. [source: Hardarson et al., 2024; Badawi et al., 2021; Kessler ISRCTN52555566]
• The task must be visuospatial and actively engaged. Practical meaning: Tetris played with deliberate mental rotation, for a set time (20 minutes in the main version), not passive play or another kind of distraction. Control conditions in trials (podcast, reading a Wikipedia article, classical music) were chosen precisely because they are not visuospatial. [source: GAINS-2 protocol; Kanstrup et al., 2021 abstract; ISRCTN52555566]
• Count, don't interpret. Practical meaning: progress is judged by the diary count of intrusions, ideally against a baseline week. [source: Hardarson et al., 2024; GAINS-2 protocol]
• Collaborative choice of target. Practical meaning: pick together, usually the most frequent or most distressing intrusion. [source: Hardarson et al., 2024]
• Guided start, then self-management. Practical meaning: the clinician guides the first session so the client can repeat the procedure alone after intrusions; extra guided sessions are offered, not imposed. [source: Hardarson et al., 2024; GAINS-2 protocol]
• Low intensity and scalable. Practical meaning: trained non-specialists (psychology students with structured training, role-play assessment and weekly supervision) delivered it in the Iceland study; it can be given remotely. [source: Hardarson et al., 2024]
• Ask about adverse events every contact. Practical meaning: at each session, ask what has happened since last time, including any worsening, and signpost risk to appropriate care. [source: Hardarson et al., 2024; GAINS-2 protocol]
• It sits within, not instead of, wider care. Practical meaning: a person with PTSD, depression or risk still needs assessment and an offer of standard treatment; the task targets one symptom. [synthesis]
• Memories are the client's experience. Practical meaning: the method works only with memories that already intrude; never use it, or any imagery, to search for or 'recover' memories. [synthesis, in line with house rules]

4. Intervention inventory

The published procedures are listed in the order they are used. Trials delivered parts of the psychoeducation by short videos; these are not publicly available, so the wording below is illustrative. [source for section: Hardarson et al., 2024; GAINS-2 protocol; Badawi et al., 2021; Kanstrup et al., 2021 abstract; ISRCTN52555566]

4.1 Screening and safety check

• Purpose / when: before anything else, to confirm the target (intrusive memories of a Criterion A event) and rule out the exclusions in Section 2.
• Steps: (1) Confirm the traumatic event briefly (what type, when), without asking for details. (2) Ask whether images or other memories of it come to mind unbidden, and roughly how often in the past week (trials required at least 2–5 a week). (3) Screen for psychosis, mania, acute suicidality, recent severe self-harm and problematic substance use; trials used a structured interview such as the MINI. (4) Baseline measures used in trials: PCL-5, PHQ-9 or PHQ-2, GAD-7 or GAD-2, functioning measures. (5) Ask whether the client is having other trauma treatment; decide whether this fits alongside it (Section 2C) or should wait. [source: Hardarson et al., 2024; GAINS-2 protocol; ISRCTN52555566]
• Example language (illustrative): "This approach works on one thing: the pictures of what happened that pop into your head when you don't want them. I won't ask you to tell me the story of what happened."
• Watch for: current ongoing trauma exposure (e.g. continuing violence at home), which needs safety planning first [synthesis]; intrusions that are mainly thoughts or worries about the future rather than memories of a past event, which this task does not target [synthesis].

4.2 Psychoeducation on intrusive memories

• Purpose / when: at the baseline session, so the client can recognise and count intrusions accurately.
• Steps: (1) Define an intrusive memory: a memory of the trauma, usually a vivid image, that comes to mind suddenly and unbidden. GAINS-2 described them as memories that "pop suddenly into your mind when you don't want them to". (2) Distinguish them from deliberately thinking about the event and from general worry or rumination. (3) Normalise: intrusions are a common reaction after trauma. (4) Explain that the client will count them. Trials used short videos for this step. [source: GAINS-2 protocol; Hardarson et al., 2024]
• Example language (illustrative): "An intrusive memory is like a snapshot or a short clip from that day that jumps into your mind by itself. If you choose to think about what happened, that doesn't count; it's the ones that just arrive."
• Watch for: the client counting every thought about the event (inflated counts) or only the most severe ones (deflated counts); check with one or two examples from the past day [synthesis].

4.3 Listing and labelling the client's intrusions

• Purpose / when: baseline session; creates the menu of targets and lets each be counted separately.
• Steps: (1) Ask the client to name each distinct intrusive memory they have. (2) For each, record a label of only a few words (the Iceland paper's example: "dark room"); do not ask for a description. (3) Keep the list visible to both of you (the Iceland team shared the screen of the list on video calls). (4) Add new intrusions to the list as they come up. [source: Hardarson et al., 2024]
• Example language (illustrative): "Just give each picture a short name, two or three words, enough that you'll know which one you mean. No need to tell me what's in it."
• Watch for: the client starting to recount the trauma; gently redirect to a label. Several labels that describe the same image should be merged [synthesis].

4.4 Intrusion diary (monitoring)

• Purpose / when: from baseline onwards, to measure frequency per intrusion and judge progress.
• Steps: (1) Give a daily diary (paper or app). The Iceland study used a daily paper diary split into morning, afternoon, evening and night; GAINS-2 asked each day whether intrusions occurred and how many, with daily text or email reminders. (2) Ideally keep one baseline week before the first guided session. (3) Review the diary at every session. (4) In research versions, diary weeks were repeated at about weeks 4–5, 12 and 24, and clients rated how accurately they had kept it. Badawi et al. used phone prompts three times a day, with items on how closely each intrusion related to the memory worked on, its emotional tone, trigger and viewpoint. [source: Hardarson et al., 2024; GAINS-2 protocol; Badawi et al., 2021]
• Example language (illustrative): "Each time one of these pictures pops up, put a tick in today's box for that part of the day, and if you can, note which one on your list it was."
• Watch for: missing days; counts that rise in the first week (seen in the Iceland study and thought possibly to reflect monitoring itself), which should not be read as failure. [source: Hardarson et al., 2024]

4.5 Choosing the target intrusion

• Purpose / when: at the start of each guided session.
• Steps: (1) Look at the diary and the list together. (2) Choose one intrusion jointly, "typically the most frequent or distressing". (3) At later sessions, keep the same target if it still occurs, or pick another the client wants to reduce. [source: Hardarson et al., 2024]
• Example language (illustrative): "Looking at your week, which picture has come up most, or bothered you most? Let's work on just that one today."
• Watch for: a client choosing the least distressing image to avoid discomfort; this is acceptable as a first practice round [synthesis].

4.6 Rationale

• Purpose / when: first guided session, before the first cue; supports engagement and credibility (expectancy and credibility ratings were high in the Iceland study).
• Steps: (1) Explain in plain terms that intrusive memories are picture-like; that a memory brought to mind may be open to change for a while; and that a game that uses the mind's eye for shapes and positions may make it harder for the picture to keep intruding. (2) Present this as the developers' hypothesis. (3) Say that you will check whether it works for this client by counting. Trials used rationale videos, and the last Iceland participants also saw a video on hypothesised mechanisms. [source: Hardarson et al., 2024] [uncertain: wording of the trial videos not available]
• Example language (illustrative): "Memories that come back as pictures seem to rely on the same mental 'screen' we use for imagining shapes. The idea is to bring the picture up for a moment and then keep that screen busy with a shape game, so the memory settles back less vividly. We'll find out from your diary whether it helps you."
• Watch for: the client feeling the method trivialises their trauma ("a video game?"); see Section 5.

4.7 Teaching Tetris with mental rotation

• Purpose / when: first guided session, before the cue (so learning the controls does not use up the period straight after the reminder).
• Steps: (1) Set up the game on the device the client will use at home (the Iceland study used the free browser game at tetris.com with screen sharing; GAINS-2 used an app whose difficulty adapts to skill; Badawi used a modified tablet version with capped speed). (2) Explain mental rotation: while each block falls, look at the upcoming blocks and picture in your head how to turn and move them to fill gaps and complete lines. (3) Let the client practise briefly (Badawi: 2 minutes of practice on day 0, with the client repeating the instructions back). [source: Hardarson et al., 2024; GAINS-2 protocol; Badawi et al., 2021]
• Example language (illustrative): "Before you press anything, picture the piece turning in your head and where it would fit best. Keep doing that for each piece, and keep an eye on the ones coming next."
• Watch for: passive play (pressing keys without planning); frustration at speed; the client repeating the instruction accurately is a good sign it has been understood. [source: Badawi et al., 2021 for teach-back]

4.8 Memory reminder cue

• Purpose / when: immediately before gameplay, to bring the one target memory briefly to mind.
• Steps: (1) Name the chosen label. (2) Ask the client to bring that image to mind so they can see it in the mind's eye, briefly, without describing it aloud and without discussing it. In GAINS-2 the client instead wrote a few words for the intrusion; in Kessler's trial the client wrote down one intrusive memory. (3) As soon as the image has been brought up, move straight on to the game. [source: Hardarson et al., 2024; GAINS-2 protocol; ISRCTN52555566] The published papers do not give an exact cue duration [uncertain]; keep it to a few seconds up to under a minute [synthesis]. In the adjunct version, the imaginal-exposure session itself serves as the reminder (Section 4.12).
• Example language (illustrative): "Let's take 'dark room'. Just bring that picture to mind for a moment, so you can see it. You don't need to tell me anything about it. Okay, let it go, and start the game now."
• Watch for: the client getting absorbed in the memory or starting to talk about it (keep it brief and redirect to the game); signs of strong distress or dissociation (Section 5). Distress from bringing the memory to mind was the main anticipated risk in Kessler's trial protocol. [source: ISRCTN52555566]

4.9 Gameplay with mental rotation

• Purpose / when: straight after the reminder cue; this is the active ingredient as the developers describe it.
• Steps: (1) Client plays Tetris, using mental rotation throughout, for at least 20 minutes in the main version (the Iceland paper: "at least 20 minutes"; GAINS-2: 20 minutes; Badawi: 12 minutes in the adjunct version). (2) Stay present (on screen or in the room) during the first guided session; you can observe without talking. (3) If the image returns during play, the client notes it and returns attention to rotating the pieces [synthesis]. (4) Afterwards, ask briefly how it went and check distress. Badawi et al. rated sadness, hopelessness, fear, horror and depression on 0–10 scales before and after play. [source: Hardarson et al., 2024; GAINS-2 protocol; Badawi et al., 2021]
• Example language (illustrative): "Keep picturing each piece turning before you move it, all the way through. I'll let you know when twenty minutes are up."
• Watch for: rising distress; drifting into passive play; reported low enjoyment or concentration (both fell below the feasibility threshold in Badawi's inpatient sample), which may call for adjusting difficulty or timing. No adverse events during gameplay were reported in that study. [source: Badawi et al., 2021]

4.10 Instructions for self-guided use at home

• Purpose / when: end of the first guided session; lets the client apply the procedure to the same or other intrusions between sessions.
• Steps: (1) Agree when to use it: the trials framed it as after an intrusion occurs (the Iceland study counted how often clients played after an intrusion: mean about 3.5 times). (2) Rehearse the sequence: notice the intrusion, bring that same image briefly to mind (it may still be present), then play with mental rotation for about 20 minutes. (3) Keep counting in the diary. (4) Offer reminders (GAINS-2 sent regular reminders in the first 4 weeks, which could be switched off). [source: Hardarson et al., 2024; GAINS-2 protocol] [uncertain: the exact home instructions are not published in the papers; the steps above follow the in-session procedure]
• Example language (illustrative): "When one of the pictures pops up and you can find twenty minutes reasonably soon, do what we did today: see it for a moment, then play, turning the pieces in your head."
• Watch for: using the game to avoid all reminders or to fill every spare moment rather than as a planned procedure [synthesis]; playing without the brief reminder [synthesis].

4.11 Follow-up guided sessions and retargeting

• Purpose / when: about weekly after the first session (Iceland: second session about one week later; up to 6 in total).
• Steps: (1) Ask about adverse events and anything new since last contact. (2) Review diary counts for each labelled intrusion and how often the client used the procedure at home. (3) Keep the same target if it persists, or choose another the client wants to reduce. (4) Repeat cue plus gameplay in session. (5) Decide whether further sessions are needed or the client can continue self-guided. [source: Hardarson et al., 2024; GAINS-2 protocol]
• Example language (illustrative): "'Dark room' came up twice this week, down from nine. Do you want to keep going with that one today, or move to the next on your list?"
• Watch for: targeted intrusions falling while others stay the same, which suggests moving on rather than stopping [synthesis].

4.12 Variant: adjunct after imaginal exposure in trauma-focused CBT

• Purpose / when: for clients already in trauma-focused CBT with imaginal exposure, to add the visuospatial task after reactivation that has already happened in therapy. [source: Badawi et al., 2021]
• Steps: (1) On day 0, teach mental rotation and practise for 2 minutes; ask the client to say the instructions back. (2) After a therapy session that included at least 15 minutes of imaginal exposure, hand over the tablet at the end of the session. (3) Client plays a modified Tetris (speed capped) with mental rotation for 12 minutes. (4) In the study this was done after the first three qualifying sessions; clinicians used the playing time to finish notes. (5) Track intrusions in an app diary. [source: Badawi et al., 2021]
• Example language (illustrative): "We've finished the reliving part for today. Before you leave, play for twelve minutes, picturing each piece turning, the way we practised."
• Watch for: only usable if exposure actually happened that session (five of 23 participants dropped out because imaginal exposure was not used); finish your usual closure and grounding of the exposure session first [synthesis]. This was a feasibility study without a control group; the effects were small. [source: Badawi et al., 2021]

4.13 Variant: early single session soon after trauma

• Purpose / when: in an emergency department or similar acute setting, hours to days after a single traumatic event, to reduce the intrusive memories that develop afterwards. [source: Iyadurai et al., 2018 record; Kanstrup et al., 2021 abstract]
• Steps: (1) Check eligibility and that the person is medically able to take part (the trials were in the emergency department; Kanstrup: within 72 hours). (2) Memory reminder cue to the trauma. (3) Tetris with mental-rotation instructions. (4) Intrusion diary for the following week; follow-up at about one month. [source: Kanstrup et al., 2021 abstract] [uncertain: exact cue procedure, play duration and time window of the 2018 ED trial were not confirmed from full texts]
• Example language (illustrative): "While you wait, there's a short task that may reduce the number of times pictures of today come back to you. It involves thinking of it for a moment and then playing a game."
• Watch for: medical priorities always come first; the person's capacity to consent; it is not a substitute for later assessment if symptoms persist [synthesis].

4.14 Variant: mental cube-rotation task instead of Tetris

• Purpose / when: a non-game visuospatial task tested by Kessler's group in Bochum. [source: ISRCTN52555566]
• Steps: (1) Intrusions to be tracked are agreed at baseline and logged in an electronic diary for 2 weeks. (2) At the intervention session the client writes down one intrusive memory (the reminder). (3) The client then completes 25 minutes of mental cube rotation (80 items: work out how to turn one cube to match a second shown from another angle). (4) Diary continues for 2 weeks; a team member is present throughout and physicians are on hand. [source: ISRCTN52555566] [uncertain: results not drawn on; treat as experimental]
• Example language (illustrative): "Write a few words for the picture you've chosen. Then for each pair of cubes, work out in your head how the first one turns to look like the second."
• Watch for: the same as 4.8–4.9.

4.15 Delivery by trained non-specialists (service-level procedure)

• Purpose / when: when services want to scale delivery. [source: Hardarson et al., 2024]
• Steps: in Iceland, psychology students completed an online course, seven weekly training sessions, and recorded role-plays rated 0–6 on nine components; they had to score at least 4 on each before delivering, and had weekly group supervision plus optional individual supervision. GAINS-2 sessions were audio-recorded for fidelity, and clinical psychologists trained and monitored staff. [source: Hardarson et al., 2024; GAINS-2 protocol]
• Watch for: clear escalation routes to a qualified clinician for risk or worsening [synthesis].

5. Handling problems

The published papers report few difficulties and give almost no management guidance. They do report: no intervention-related serious adverse events; adverse events asked about at every contact; signposting to the GP or other services for suicidality or significant risk; a rise in intrusions from baseline to week 1 in the Iceland study; dropouts linked to unrelated life stressors; one client who found phone notifications aversive because a device was linked to their trauma; and below-threshold enjoyment, concentration and timely diary completion in the inpatient adjunct study. [source: Hardarson et al., 2024; GAINS-2 protocol; Badawi et al., 2021] Everything else below is [synthesis] unless tagged.

• Distress during the reminder cue. Keep the cue brief and go straight into the game, which itself pulls attention outward. If distress is high afterwards, use ordinary grounding (orient to the room, feet on the floor, describe five things in view) before ending. Next time, choose a less distressing intrusion first or shorten the cue. [synthesis; brief cue: Hardarson et al., 2024; GAINS-2 protocol]
• Dissociation (blank stare, loss of contact, feeling unreal) when the memory is brought up. Stop the cue, ground the client (name, date, place, sensory focus) and do not start play until the client is clearly present. If dissociation recurs, pause this method and assess for a dissociative presentation; use stabilisation work first. The trials did not report dissociation handling. [synthesis] [uncertain]
• Intrusions increase in the first week. Explain that counting can make people notice more, and that the Iceland study saw a similar rise before a fall; judge progress over several weeks, not one. [source for the rise: Hardarson et al., 2024; framing: synthesis]
• Target intrusion does not change after two to three rounds. Check the procedure: was the reminder brought up just before play, was mental rotation used, was play long enough (around 20 minutes)? Check that the intrusion is image-based. If the procedure is right and nothing changes, move to another target or step up to a full trauma-focused therapy (TF-CBT, CPT, EMDR). [synthesis]
• Intrusions are mainly sounds, smells or body sensations rather than images. The method was designed for image-based intrusions; it may fit less well. Try it, count, and switch to standard trauma treatment if counts do not move. [synthesis] [uncertain]
• Many different intrusions or complex, repeated trauma. Work through the list one by one, most frequent or distressing first; if the list is long and symptoms broad (mood, shame, relationships), this method alone is unlikely to be enough, so offer it alongside or before full therapy. The ICU-staff and Iceland samples included repeated and long-past trauma. [source for samples: Iyadurai et al., 2023 abstract; Hardarson et al., 2024; guidance: synthesis]
• Client feels the method trivialises their trauma ("a game?"). Acknowledge the reaction; explain that the game is used as a precise mental task, not as entertainment or distraction, and that its effect will be checked in the diary; offer full trauma therapy as an alternative or addition. [synthesis] This is a rupture risk: name it early and repair rather than persuade.
• Client wants to tell the story. Validate the wish; explain this method deliberately avoids detailed recall; offer a separate space or referral for trauma-focused therapy if they want to work on the narrative. [synthesis]
• Frustration with the game, poor skill or older clients unfamiliar with games. Practise first, use a slower or adaptive-difficulty version (GAINS-2 adapts difficulty; Badawi capped speed), and stress that score does not matter; mental rotation does. [source for settings: GAINS-2 protocol; Badawi et al., 2021; framing: synthesis]
• Low enjoyment or poor concentration (e.g. inpatients, medicated or exhausted clients). Shorten instructions, schedule play when the client is less tired, and check concentration after the session; consider whether the timing (end of an exposure session) is too demanding. [source for the problem: Badawi et al., 2021; responses: synthesis]
• Diary non-adherence. Simplify (one tick per intrusion per part of the day), use reminders, review the diary at the start of every session, and reconstruct a missed day together rather than skipping it. [source for reminders: GAINS-2 protocol; rest: synthesis]
• Not using the procedure at home. Problem-solve when 20 minutes is realistically available; agree a specific time and device; one guided session per week can carry the work if self-guided use stays low. [synthesis]
• Device or notifications are themselves trauma reminders. Allow notifications to be switched off, use another device or paper diary. [source: Badawi et al., 2021; GAINS-2 protocol allowed reminders to be turned off]
• Using the game as avoidance. If the client plays for hours or whenever any reminder appears, re-establish the structure (brief deliberate reminder, then a set period) and discuss avoidance as a maintaining factor. [synthesis]
• Ongoing trauma exposure (e.g. health workers, emergency staff, people still at risk). The method was tested in ICU staff during ongoing pandemic work; new intrusions may appear and can be added to the list. Where the client is still unsafe (e.g. domestic abuse), safety planning comes first. [source for ICU setting: Iyadurai et al., 2023 abstract; rest: synthesis]
• Risk: suicidality, self-harm, worsening depression. Assess at every contact using standard risk assessment; acute suicidality was an exclusion in the trials, and participants with risk were directed to their GP or other care. Pause the task and follow your service's risk pathway. [source: Hardarson et al., 2024; GAINS-2 protocol; ISRCTN52555566]
• Psychosis, mania, active substance misuse. These were exclusions in the trials; treat or stabilise first. [source: Hardarson et al., 2024; ISRCTN52555566; Badawi et al., 2021]
• Client in another trauma therapy. Coordinate with the treating clinician; Kessler excluded people having ongoing exposure-based therapy, while Badawi used the task inside exposure therapy and GAINS-2 allowed other treatment. Agree one plan so the two do not compete. [source: ISRCTN52555566; Badawi et al., 2021; GAINS-2 protocol]
• Possible new memories appearing or uncertainty about what happened. Do not explore, interpret or confirm; work only with memories the client already has as intrusions, and never use the reminder step to search for memories. [synthesis, per house rules]

Sources

Sources:

• Hardarson et al. (2024) Developing a brief cognitive task intervention to reduce long-standing intrusive memories of trauma: a feasibility study with remote delivery for women in Iceland. Clinical Psychology in Europe 6(1), e11237 (full text)
• GAINS-2 protocol: A Brief Cognitive Task Intervention for NHS Staff Affected by COVID-19 Trauma (NCT05616676), ClinicalTrials.gov document (full protocol, partly truncated)
• Badawi A, Steel Z, Mahoney C, et al. (2021) Feasibility of an adjunctive cognitive task in the treatment of posttraumatic stress disorder. Discover Psychology 1, 11 (full text)
• ISRCTN52555566: Investigation on a novel approach for reducing intrusions in patients after a traumatic event (Kessler, Bochum) (registry record)
• Kanstrup M, et al. (2021) Reducing intrusive memories after trauma via a brief cognitive task intervention in the hospital emergency department: an exploratory pilot RCT. Translational Psychiatry 11, 1–15 (DOAJ record) (abstract only)
• Iyadurai L, et al. (2023) Reducing intrusive memories after trauma via an imagery-competing task intervention in COVID-19 intensive care staff: a randomised controlled trial. Translational Psychiatry 13, 290 (Regensburg repository record) (abstract only); also Cambridge repository record and Southampton record
• Iyadurai L, et al. (2018) Preventing intrusive memories after trauma via a brief intervention involving Tetris computer game play in the emergency department: a proof-of-concept RCT. Molecular Psychiatry 23, 674–682 (UEA repository record) (citation only)

Further reading (not drawn on): the 2018 and 2021 full texts on PubMed Central and the UEA PDF; the 2018 trial's supplementary procedure document; the Kanstrup 2021 publisher page. Details from these are marked [uncertain].

Books and papers cited by author, year, title: Iyadurai et al. (2018), Molecular Psychiatry; Kanstrup et al. (2021), Translational Psychiatry; Iyadurai et al. (2023), Translational Psychiatry; Hardarson et al. (2024), Clinical Psychology in Europe; Badawi et al. (2021), Discover Psychology. No treatment manual for this intervention is publicly available; the trial versions are delivered through study-specific videos and platforms (e.g. i-spero®).