Q. Can the borderline personality disorder start at age 37? There were no symptoms before this time.

A. I have not seen BPD start after mid 20's. BPD might come to clinical attention later in life, but most individuals had some of their BPD symptoms as teenagers. Like any other medical illness, BPD can evolve with time. Symptoms might worsen over time or even change. For example, cutting as a teenager might give way to depression or migraines or hypersexuality as an adult. All arise from the same chemistry when they co-occur in the same person. This co-morbidity of behaviors is called parsimony of diagnosis. It basically means you have one disease with many symptoms. Our jobs as physicians is to link all these behaviors into one illness and determine an effective course of treatment to address all the symptoms.