Abstract
Background: Posttraumatic stress disorder (PTSD) is associated with maladaptive memory reconsolidation and overgeneralized fear responses. EMDR therapy promotes trauma reprocessing by activating the brain's intrinsic memory reconsolidation mechanism, facilitating memory updating, and abandoning outdated emotional schemas. Ketamine may also facilitate adaptive updating of traumatic memory due to its neurobiological and subjective effects. Research remains limited on the combined effects of EMDR therapy and ketamine for PTSD. Ketamine Assisted EMDR Therapy™ (KA-EMDR) integrates low-dose sublingual ketamine with EMDR memory reprocessing, providing a potentially synergistic trauma treatment by improving memory access, reducing hyperarousal, and enhancing adaptive reconsolidation of fear-based memories.Objective: To examine whether incorporating low-dose sublingual ketamine into EMDR therapy reduces PTSD symptom severity and functional impairment in individuals with PTSD.Methods: A retrospective clinical chart review examined data collected from eight clients with PTSD in a private psychotherapy practice who received KA-EMDR. Sublingual ketamine (37.5-75 mg) was self-administered during EMDR reprocessing after memory activation. The International Trauma Questionnaire (ITQ) assessed PTSD symptoms and functional impairment at baseline and after four KA-EMDR reprocessing sessions (T1). Paired-samples t-tests analysed symptom changes. Clients also completed a subjective experience questionnaire.Results: PTSD symptom scores significantly decreased from baseline (M = 15.50, SD = 2.98) to T1 (M = 9.88, SD = 4.94), t(7) = 3.21, p < .05, with a large effect size (g = 1.01). Functional impairment scores significantly declined from baseline (M = 8.50, SD = 2.78) to TI (M = 5.25, SD = 3.24), t(7) = 2.60, p < .05, with a large effect size g = 0.82. Clients reported reduced fear, increased self-compassion and emotional clarity, less resistance, and minimal adverse effects.Conclusions: KA-EMDR may be a promising treatment for PTSD, particularly for those with treatment-resistant trauma. Larger randomized controlled studies are needed to confirm these findings.