The book is divided into two parts containing three chapters each. Part one, titled “Attachment Trauma and Psychiatric Disorders,” reviews attachment theory, mentalizing, mindfulness, posttraumatic stress disorder (PTSD), dissociative disorders, and complex PTSD. The author makes a case for a developmental understanding of trauma while providing a comprehensive but brief overview of the literature. Similarly, the second part, titled “Treatment and Healing,” begins with a review of evidence-based treatments for trauma-related disorders, including PTSD and borderline personality disorder. Allen respects the supporting science that has necessarily used diagnostic categories but advocates for a more developmental and individualized approach. As he describes common treatment modalities, he identifies the common threads between them to develop his concept of plain old therapy. He then applies the plain old therapy approach to depression, anxiety, eating disorders, self-injury, and beyond. He asserts, quite effectively, that all treatments with an evidence base are compatible with a mentalizing approach.