About 60% of all depressive patients suffer from mental health comorbidities. In many cases, the comorbidity of these depressive patients is posttraumatic stress disorders (PTSDs), complex PTSD (C-PTSD), and/or moderate to severe dissociative disorders. While structured research in this patient group is still in its infancy, in this chapter we cover what we have learned by treating many of these complex patients. It is clear that the greater the complexity with which patients present, the more psychoeducation, resourcing, and eye movement desensitization and reprocessing (EMDR) memory reprocessing sessions are needed. Often, complex patients have faced years of treatment and are not diagnosed accurately. Those considered treatment resistant are often patients with a history of trauma/PTSD or a dissociative disorder. The first step for these patients is to help them understand their disorder and to stabilize them before any EMDR processing. We have observed that when these steps are taken, complex and dissociative patients make real progress with their trauma and then their depressive disorder.