The problem with the criteria from lets say the DSM IV is that it is actually too generalized.

Example: I started reading Linehan's book. In it, it talked about how not all BPD's under control their anger. Many over control it. So if you express your anger too much OR try to keep anger pushed down, you still met the criteria.

Also, overtime, due to experiences, and education (even therapy), the symptoms can lessen and even go away. I was told that there are over 200 ways BPD can present itself. So very few of us fit the mold exactly.

When I'm able to stop SI'ing, I don't even meet the minimum 5 out of 9 criteria...but I still have BPD.