Reducing intrusive memories after trauma via a brief cognitive task intervention in the hospital emergency department: an exploratory pilot randomised controlled trial

Abstract

Intrusive memories are common after trauma, and can cause significant distress. Interventions to prevent/reduce the occurrence of this core clinical feature of posttraumatic stress disorder are needed; they should be easy to deliver, readily disseminated and scalable. A novel one-session intervention by Iyadurai et al. 2018, Molecular Psychiatry, resulted in intrusion reduction over the subsequent week. Its feasibility in a different setting and longer-term effects (>1 month) need investigation. We conducted an exploratory open-label pilot randomised controlled trial (RCT) to investigate the feasibility and effects of a brief behavioural intervention to reduce intrusive memories in trauma-exposed patients in a Swedish hospital emergency department (ED). Participants (final N = 41) were randomly allocated to either intervention (including memory reminder cue then visuospatial cognitive task "Tetris" with mental rotation instructions) or active control (podcast) condition within 72 h of presenting to the ED (both conditions using their smartphone). Findings were examined descriptively. We estimated between-group effect sizes for the number of intrusive memories post-intervention at week 1 (primary outcome) and week 5 (secondary outcome). Compared to the control condition, participants in the intervention condition reported fewer intrusive memories of trauma, both at week 1 and week 5. Findings extend the previous evaluation in the UK. The intervention was readily implemented in a different international context, with a mixed trauma sample, with treatment gains maintained at 1 month and associated with some functional improvements. Findings inform future trials to evaluate the capacity of the cognitive task intervention to reduce the occurrence of intrusive memories after traumatic events.

Conflict of interest statement

E.A.H. reports serving on the board of trustees of the charity MQ: Transforming Mental Health but receives no remuneration for this role. E.A.H. receives royalties from books and occasional fees for workshops and invited addresses; receives occasional consultancy fees from the Swedish agency for health technology assessment and assessment of social services; and reports grants from The OAK Foundation (OCAY-18-442), the Lupina Foundation and the Swedish Research Council (2017-00957). L.I. is on the British Association for Behavioural and Cognitive Psychotherapies Scientific Committee and via this role is funded to attend the Annual Conference. The other authors have no conflict of interest to declare.

Figures

Fig. 1. Participant flow through the study.

CONSORT diagram.

Fig. 2. Number of intrusive memories of the traumatic event in the intervention and active control conditions.

Intervention = cognitive task (trauma memory reminder cue plus Tetris computer game play using mental rotation); Active control condition = attention placebo task (listening to podcast). a Violin plots displaying mean number of intrusive memories recorded in a daily diary during week 1 after completing the intervention/control procedure following a traumatic event. Error bars depict standard errors. Points depict the total number of intrusive memories (per week) of each participant. Violins depict smoothed density. Plots were created with the pirate plot function of the ‘yarrr’ package (Version 0.1.5) in R. b Violin plots displaying mean number of intrusive memories recorded in a daily diary during week 5 (as above). c Bar graphs displaying mean number of intrusive memories recorded in a daily diary during week 1 after completing the intervention/control procedure following a traumatic event. Error bars depict standard deviations (for comparison with Iyadurai et al., Fig. 2). d Bar graphs displaying mean number of intrusive memories recorded in a daily diary during week 5 (as above). e Frequency scattergraphs displaying the time course of the number of intrusive memories recorded in a diary during week 1 after completing the intervention/control procedure following a traumatic event. The size of the circles represents the number of participants who reported the indicated number of intrusive memories on that particular day, scaled separately for each condition (see also Supplementary Information for Fig. 2e). f Frequency scattergraphs displaying the time course of the number of intrusive memories recorded in a diary during week 5 (as above).