Borderline Personality Disorder, Trauma, and the Bonds That Shape Us Why you don’t need “big trauma” to develop BPD—and why PTSD doesn’t tell the whole story Borderline Personality Disorder (BPD) is one of the most misunderstood mental health diagnoses. People often assume that BPD only develops in response to severe, obvious trauma. While trauma can be a factor, many individuals with BPD do not report what society tends to label as “major trauma.” This misunderstanding can l