My wife did DBT and CBT therapy at Bellwood in Toronto. It cost a fortune and I felt it was a last resort too. What experimental treatment is your wife getting into
Ketamine infusions and TDS stimulation. The Ketamine cost is $1500. The TDS will be covered by insurance at $100 copay for 6 weeks. So $2100 altogether, which would be a bargain if it helps. The idea is to actually re-wire the connections in her brain. It's advertised to help those with major depression that do not respond to medication, and for those with PTSD. From my internet research, there is some reported success with BPD - but then again many people with BPD are also depressed and do not respond to medication, and are also diagnosed with PTSD.