It can take a long time to get the proper diagnosis. I think they do this sort of like a mechanic does it when you have a problem with you're car..They start with the most obvious issue and try to "fix" that..but then if something comes along of if it does not work they look at other issues. Also, I think that it can take a long time before we really open up..other times it can be hard explaining things..so they must observes..thinking pattern, behaviors, reaction to medication, reaction to life issues..BP and BPD is similar for some stuff, but so different for other things. At 18, I was told I was BPD after a few appointment...10 years later..it was humour problems,,another 10 years later..post traumatic..and now..probable ADHD and probable cycloramic disorder...see how it all can change,,,depending of who is evaluation, how you are, ..I'd say it's really really important to have a few points of view and to talk to you're psychologist, and mostly a psychiatrist. Good Luck.