Great questions! You raise a lot of important points. Yes personality disorders overlap and more often than not those with one diagnosis also meet criteria for at least one other. The most common PD diagnosis continued to be NOS — not otherwise specified — indicating that the actual diagnoses are not specific enough. As for why diagnose at — this is a complicated question but I’ll just say that ideally if giving a diagnosis it should be linked to one or more treatments that can help the person and possibly an etymology that gives you ideas of how to get to the root of the problem. You have raised so many important questions ivyhonk they go beyond the ability to address them in a comment so I will try to do so more completely in an article that will hopefully clarify what I didn’t present cleatly enough here. Thank you for your comment and questions and for pointing out areas I missed in the article. I appreciate the feedback and conversation. If there are other questions or areas you think need to be addressed please add them below and I will include them in my more complete response.