Feasibility of Intensive Eye Movement Desensitization and Reprocessing Therapy for Adults with Mild Intellectual Disability or Borderline Intellectual Functioning and Posttraumatic Stress Disorder in a Tertiary Mental Health Care Setting: A Nonconcurrent Single-Case Design Study

Introduction Adults with mild intellectual disability (MID; IQ 50–70) or borderline intellectual functioning (BIF; IQ 70–85) are at elevated risk for posttraumatic stress disorder (PTSD). Evidence for intensive trauma-focused treatment in this group is scarce, whereas studies in people without intellectual disabilities suggest that intensive formats improve treatment efficiency and reduce drop-out. This study examined the feasibility, potential effectiveness, and safety of intensive Eye Movement Desensitization and Reprocessing (EMDR) for adults with MID-BIF, PTSD, and complex comorbidities in tertiary mental health care.Methods A nonconcurrent single-case A – B – A design was applied. Six adults received up to 16 EMDR sessions across four weeks, delivered by rotating therapists during a brief inpatient admission including an activation program. PTSD symptoms, diagnosis, and adverse events were assessed.Results Five participants showed significant PTSD symptom reduction; three no longer met diagnostic criteria. All completed treatment without drop-out or adverse events.Conclusion Intensive EMDR appears feasible, safe, and potentially effective for adults with MID-BIF and PTSD in tertiary care.