A Digital Cognitive Intervention for Intrusive Memories After Trauma

The number of intrusive memories related to the traumatic event, as recorded by participants in a online diary.

Number of intrusive memories of traumatic event(s) recorded by participants in a brief daily online diary for 7 days.

The CAPS-5 is a structured clinical interview assessing the 20 DSM-5 PTSD symptoms. Symptom frequency and intensity are assessed separately but converted into a single 5-point severity scale for each item: 0 (absent), 1 (mild/subthreshold), 2 (moderate/threshold), 3 (severe/markedly elevated), and 4 (extreme/incapacitating). The total severity score is calculated by summing these 20 items, ranging from 0 to 80, with higher scores indicating greater PTSD symptom severity. Furthermore, the CAPS-5 utilizes the SEV2 rule (symptom severity rating of 2 or higher) for diagnostic purposes: a symptom is considered present, and subsequently counted toward a PTSD diagnosis, only if its severity rating is 2 or higher. Conceptually, the SEV2 rule establishes a stringent threshold, generally requiring a minimum symptom frequency of at least twice a month and an intensity of "clearly present".

This 7-item questionnaire assesses several characteristics of intrusive memories. These characteristics include frequency (7-point categorical response ranging from "never" to "many times a day"); distress (0 = not at all to 10 = extremely); disruption to concentration (0 = not at all to 10 = extremely); interference with ongoing activities, including the degree of interference (0 = not at all to 10 = extremely) and duration of interference (6-point categorical response ranging from less than 1 minute to more than 60 minutes); impact on work functioning (0 = not at all to 10 = extremely); and impact on functioning in other areas of life (0 = not at all to 10 = extremely).

A 2-item questionnaire assessed participants' immediate subjective experience after each intervention session: distress experienced during the procedure, rated from 0 (not at all distressing) to 10 (very distressing), and acceptability of the intervention task, rated from 0 (not at all acceptable) to 10 (very acceptable).

The PCL-5 is a 20-item self-report questionnaire that assesses the presence and severity of PTSD symptoms experienced in the past month. Each of the 20 items is rated on a 5-point Likert scale ranging from 0 (Not at all) to 4 (Extremely). The total symptom severity score is calculated by summing the scores of all 20 items. The total score ranges from 0 to 80. Higher scores indicate greater severity of PTSD symptoms. (Note: A 5-point change represents a minimum threshold for treatment response, and a 10-point change indicates a clinically meaningful improvement).

The IES-R is a 22-item self-report questionnaire designed to measure subjective distress caused by traumatic events during the past seven days. It assesses three domains of post-traumatic stress: intrusion, avoidance, and hyperarousal. Each of the 22 items is rated on a 5-point scale according to symptom severity: 0 (Not at all), 1 (A little bit), 2 (Moderately), 3 (Quite a bit), and 4 (Extremely). The total score is calculated by summing the scores of all 22 items, yielding a total score range from 0 to 88. Lower scores indicate less distress, while higher scores indicate more severe post-traumatic stress symptoms. A total score of 33 or over signifies the likely presence of PTSD.

The Beck Depression Inventory-II (BDI-II) is a 21-item self-report instrument used to assess the existence and severity of depressive symptoms, covering emotional (e.g., sadness, hopelessness), cognitive (e.g., self-reproach, worthlessness), somatic (e.g., fatigue, appetite loss), and behavioral (e.g., loss of interest, social withdrawal) dimensions. Each of the 21 items consists of four statements describing increasing levels of severity, rated on a 4-point scale ranging from 0 (not present) to 3 (severe). The total score is calculated by summing the scores of all 21 items, with a total score range from 0 to 63. Higher scores indicate more severe depressive symptoms.

The State Anxiety subscale of the State-Trait Anxiety Inventory (STAI-Form Y-I, S-AI) comprises items 1 to 20 of the inventory. Half of the items describe negative emotions and the other half describe positive emotions. It is designed to evaluate immediate or recent situational experiences of fear, tension, worry, and nervousness, making it particularly useful for assessing state anxiety under stressful conditions. Each of the 20 items is rated on a 4-point scale: 1 (not at all), 2 (somewhat), 3 (moderately so), and 4 (very much so). The S-AI total score is calculated by summing the 20 items, yielding a total score range from 20 to 80. Higher scores reflect a greater severity of the subject's current state anxiety symptoms.

The Work and Social Adjustment Scale (WSAS) is a 5-item self-report scale designed to measure the degree of functional impairment in day-to-day activities, including work, home management, social leisure activities, private leisure activities, and close relationships. Each of the 5 items is rated on a 9-point scale ranging from 0 (not at all impaired) to 8 (very severely impaired). The total score is calculated by summing the scores of all 5 items, yielding a total score ranging from 0 to 40. Lower scores indicate better functioning, whereas higher scores indicate greater functional impairment. Clinical thresholds are as follows: below 10 (subclinical), 10 to 20 (significant functional impairment), and above 20 (moderately severe or worse psychopathology).

The Borderline Symptom List-23 (BSL-23) is a 23-item self-report instrument designed to assess the severity of borderline personality disorder symptomatology over the past week, based on the criteria established by Bohus et al. (2009). Each item is rated on a 5-point Likert scale ranging from 0 ("not at all") to 4 ("very strong"). The total score is calculated as the mean of all valid items (sum of item scores divided by the number of answered items). The resulting score ranges from 0.0 to 4.0, with higher scores indicating greater severity of borderline symptoms. In addition, the scale includes a visual analog scale (VAS) to assess the participant's overall personal state during the past week. This scale ranges from 0% (absolutely down) to 100% (excellent) and is recorded as a supplementary indicator.

Description: Number of intrusive memories of traumatic event(s) recorded by participants in a brief daily online diary for 7 days.

This 4-item questionnaire assesses the number of any new traumatic events, new treatments received and the occurrence of adverse events since the last assessment.

A 4-item questionnaire (0=not at all to 10=very) assessed participants' subjective experience of the intervention: ease of use; perceived helpfulness; willingness to use the intervention if intrusive memories recur in the future; whether they perceived the task as related to their condition during the experiment.

Number of trauma-related intrusive memories assessed via a single item.

At each intervention, participants are asked whether they perceived any image via a single-item binary choice (Yes/No). If the response is "Yes," an open-ended verbal description is required.