A Brief Technique to Reduce Flashbacks of Sexual Trauma in an Adolescent: Proof-of-Concept Case Study Using Imagery Interference

Background: Trauma exposure, including sexual harm, is prevalent in adolescents. A key resulting symptom relates to reexperiencing mental images of trauma, such as intrusive memories and flashbacks. Established treatments are used to address flashback memories but are hard to access, often leave remaining symptoms, and require extensive exposure to traumatic materials. An emerging approach with adult populations suggests intrusive imagery symptoms can be precisely targeted with simple cognitive tasks. Objective: We describe a first proof-of-concept demonstration of an imagery interference technique in a 15-year-old to target residual flashback symptoms after a course of treatment for posttraumatic stress disorder (PTSD) following sexual trauma, to lay the groundwork for further evaluations. Methods: A case study (Mia) was presented, drawing from routine clinical practice within the United Kingdom's National Health Service. After 23 sessions of trauma-focused cognitive behavioral therapy, Mia received the imagery interference technique at session 24 and returned a month later for session 25 (the final session). The technique involved playing Tetris within a wider protocol informed by the science of memory malleability (eg, including brief memory recall and working memory taxation). Memory ratings (frequency, vividness, and distress) were assessed before and immediately after training on the technique and a month later. Symptoms of PTSD, anxiety, and depression were gathered at the first and final sessions. Views from Mia and her parents were also obtained. Results: For the specific flashback targeted by Mia, vividness reduced within the session (40% to 15%), distress reduced within the session (40% to 15%) and a month later (then to 10%), and frequency reduced a month later (once to zero times per week; 100% reduction). Nontargeted flashbacks also reduced in frequency (from 4 times to 1 time per month; 75% reduction). Mia described the memories as more "distant." Symptoms of PTSD, depression, and anxiety reduced overall. Conclusions: Pending further rigorous testing beyond this single case, the imagery interference approach has potential as a low-intensity and early intervention for adolescents to address intrusive imagery of trauma, such as sexual harm, and also in other clinical contexts (eg, anxiety).