Eye-Movement Desensitization and Reprocessing (EMDR) Therapy is a trauma based therapy that has shown to be clinically effective at treating Post-Traumatic Stress Disorder. A traumatic event can result in PTSD when an individual is not able to process the event in a healthy way at the time of the event. It is similar to Exposure Therapy in that it allows the individual to revisit the traumatic event and process it in a healthy way.
With DPDR and other Dissociative Disorders, EMDR may or may not be effective. Below are excerpts from two case studies: one displaying the possible efficacy of EMDR and Dissociation and another displaying the possible inefficacy of EMDR and Dissociation.
- In the subanalysis of the study, the authors pointed out that patients with a dissociative subtype of PTSD had a similar and favorable response to trauma focused treatments compared to those without the dissociative subtype, so this subgroup could benefit from this treatment and should not be excluded. 
- The nonresponders had higher levels of dissociation (depersonalization and derealization) and numbing symptoms, but other PTSD symptoms, such as avoidance, hyperarousal, and intrusion, were not significantly different.