A history of childhood trauma and ongoing dissociation are common in clients with Borderline Personality Disorder (BPD). Symptoms that occur in clients who have Complex PTSD or dissociative disorders (OSDD or DID) have a significant overlap with those of BPD, such as self-harm, suicidality, hearing voices, alterations in sense of self and states of consciousness, amnesia, depersonalization, chronic dysregulation, relational destabilization, and phobic avoidance of traumatic experiences. While many approaches focus on symptom management in BPD, we will describe a practical trauma-informed approach that emphasizes the need to identify and work with the individual's unintegrated inner structural organization as a means to address the root causes of symptoms.