The Effect of a Visuospatial Interference Intervention on Posttraumatic Intrusions: a Cross-over Randomized Controlled Trial

: Intrusive memories form a core symptom of Posttraumatic Stress Disorder (PTSD). Based on concepts of visuospatial interference and memory-updating accounts, technological innovations aim to attenuate such intrusions using visuospatial interventions.: This study aims to test the effect of a visuospatial -based intervention versus a verbal condition () and a never-targeted control () on intrusion frequency.: A randomized crossover trial was conducted including  = 38 PTSD patients who had at least 3 distinct intrusive memories of trauma. After both 2 weeks (intervention 1) and 4 weeks (intervention 2), one of the three memories was randomly selected and either the visuospatial intervention (memory reminder of a traumatic memory + ) or verbal condition (reading a article + answering questions) was performed on their first memory in randomized order. In the week 4 session, the patient conducted the other intervention condition on their second memory (crossover). The third memory was never targeted (). Daily occurrence of intrusions over 8 weeks was collected using a diary and analysed using mixed Poisson regression models.: Overall, there was no significant reduction in intrusion frequency from either intervention compared to each other, and to control (relative risk /: 0.947;  = .31; relative risk /: 1.060;  = .15; relative risk /: 1.004;  = .92).: There was no effect of either intervention on intrusions when administered in a crossover design where participants received both interventions. Design shortcomings and consequences for future studies are discussed.