BPD can either require referral to FAA HQ or be disqualifying. You'll have to submit all related records. The FAA will be looking to see if the condition has manifested itself by overt acts. If so, expect denial. To get an idea of whether your condition would be acceptable, you should consult a HIMS AME (that's consult, not submit an application for a certificate).
I cannot find any thing from the FAA about dialectic behavior therapy (DBT). Again, consultation with a HIMS AME would be your best bet.
To find a HIMS AME, Google "FAA HIMS AME list".