Bottomline is that, after reading through a few sources, Personality Disorders have no definite accurate scale on which to measure or compare. Take BPD and Bipolar for an example. It was once thought that BPD was Bipolar but psychologists found that BPD does not have the up and down episodes of Bipolar. BPD's up and down can be influenced by immediate changes whereas Bipolar does not. Schizophrenic can also be confused with BPD because, in my opinion, both are confused with their choices and "communicate" with themself... I'm not really sure.