Lóa Project: An Exploratory Pilot Randomised Controlled Trial of a Remotely-delivered Brief Cognitive Intervention to Reduce Intrusive Memories of Trauma for Women in Iceland

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

A 20-item questionnaire assessing the severity of PTSD symptoms corresponding to the DSM-5 criteria for PTSD. Symptoms are rated on a 5-point Likert-scale.

A 9-item questionnaire assessing depression symptoms and their severity. Items are scored from 0 (i.e., not at all) to 3 (i.e., nearly every day).

A 7-item questionnaire designed as a screening tool for symptoms of GAD and their severity. Items are scored from 0 (i.e., not at all) to 3 (i.e., nearly every day).

6 self-rated items assessing the frequency of unwanted memories of the trauma in the previous week (on a 7-point scale, from never to many times a day) and the level of distress, nowness, reliving, disconnectedness and whether different triggers are associated with unwanted trauma memories (on an 11-point scale, from 0 to 100). Higher scores indicate more unwanted memories, higher levels of distress/nowness/reliving/disconnectedness and more different triggers.

Assessed with six self-rated items anchored to the past week: two items assessing concentration difficulties in general and due to intrusive memories (11-point scale; high scores indicating more difficulties), one item assessing duration of disruption after experiencing intrusive memory (<1 minute to > 60 minutes), two items assessing sleep disturbance due to intrusive memories (11-point scale; higher scores indicating more sleep disturbance) and one item assessing the degree to which intrusive memories affected stress levels (0 = not at all; 10 = very much).

Assessed with two self-rated items, one assessing the degree of distress associated with intrusive memories and the other assessing how vivid they were in the past week (both rated on an 11-point scale, 0 = not at all; 10 = very distressing; 0 = not at all; 10 = very vivid).

Assessed with four items. One question is self-rated: "Have the intrusive memories affected your ability to function in your daily life?" on an 11-point scale; higher score indicating greater impact on functioning. The other question is open-ended: "How have the intrusive memories affected your ability to function in your daily life in the past week?"). We will also explore whether there is a link between the content of participants' intrusive memories and specific domains of functioning - in open-ended discussion and using questions (asked at baseline) such as: "Are there any specific activities that you would like to do, but avoid because they are linked to your intrusive memories?" and "What change in your intrusive memories would make a meaningful difference in your life?" along with (asked at follow-ups, after the intervention/control task) "Since starting the study, are there any specific activities that you used to avoid (due to your intrusive memories), but now do more often?"

A self-report questionnaire assessing functional impairment across three domains: (1) Work/school, (2) social, and (3) family life. Domains are measured on an 11-point Likert scale, ranging from 0 (i.e., not at all) to 10 (i.e., extremely). The scale will be adapted to assess functional impairment associated with intrusive memories.

A 12-item questionnaire assessing difficulties due to health conditions, including mental or emotional problems (with reference to study event). Scores range from 1 ("none") to 5 ("extremely/cannot do"). Lower scores indicate better functioning.

A 4-item a patient-generated outcome measure of symptom-change after therapy/interventions, consisting of four items measuring three domains: problems (two items), function (one item), and well-being (one item). The patient chooses which symptoms or problems are most important to measure over the course of an intervention.

A single item assessing perceived health status on a 4-point scale (very good to very bad). The scale is reverse-scored; higher scores indicate better health.

A 7-item self-report questionnaire assessing the frequency of disruptive nocturnal behaviours (e.g., acting out dreams, episodes of terror or screaming) common in PTSD. Respondents report symptoms over the past month on a 4-point Likert scale, ranging from 0 (never in the past month) to 3 (three or more times each week). Total score ranges from 0 to 21. A clinical score ≥ 4 will be used, which discriminates between participants with and without PTSD.

2 self-rated items; one assesses the extent to which the respondent is experiencing poor sleep (with reference to study event) on a 5-point scale (from not at all to very much), one assesses the number of nights in the week the respondent experiences sleep problems on 5-point scale (from 0-1 to 5-7 nights). Both 5-point scales are reverse scored (0 - 4) then summed. Possible total scores range from 0-8; higher values indicate better sleep.

8-items drawn or modified from both the Temporal Orientation Scale and the Zimbardo Time Perspective Inventory. Respondents rate how true statements are for them on a 5-point scale, from not at all true (1) to very true (5) (e.g., "My plans about the future are pretty well laid out", "It is best to live day-to-day").