The efficacy of EMDR therapy in adults with a severe intellectual disability and posttraumatic stress disorder

Background: Individuals with severe intellectual disabilities (SID; IQ 20-35) are believed to be at heightened risk of developing posttraumatic stress disorder (PTSD). However, research targeting trauma treatment in individuals with SID remains limited, and controlled intervention studies are scarce.Objective: To investigate the effectiveness of Eye Movement Desensitization and Reprocessing (EMDR) storytelling method in seven adults with SID and PTSD.Method: A multiple baseline design was used in seven adults with SID and PTSD to evaluate the efficacy of the EMDR storytelling method in reducing dysfunctional behaviours, PTSD symptoms, and challenging behaviours immediately after treatment and at three-month follow-up assessment.Results: Immediately after EMDR therapy and at three-month follow-up, significant reductions in dysfunctional behaviours and PTSD symptoms were observed at group level. At individual level, reductions in PTSD symptoms were observed in most participants, whereas results for dysfunctional behaviours were mixed. No group-level changes were found for challenging behaviours while individual outcomes were stable for the total score but varied across the BPI subscales (self-injury, stereotypical, and aggressive behaviours). No sessions were discontinued prematurely, and no adverse events were reported.Conclusions: This study provides preliminary support for the safety, suitability, and potential efficacy of the EMDR storytelling method in reducing PTSD symptoms.