That would be the Holy Grail of trauma therapy but no one I know has found it, or rather they haven’t found a way to reliably replicate it.
Marsha Lineham was in the middle of a period of deep disparity had a deeply religious experience which seems to have transformed her. She had been suicidal and felt beyond help, but the experience helped her turn her life around.
She went on to found dialectical behavioral therapy and programs for patients with borderline disorder. The therapy emphasis learning skills which help patients to learn to calm down, manage emotions and such.
However, the therapy isn’t a one time event and it’s interesting that Lineham didn’t attempt to duplicate religious experiences to help patients.
Thats interesting, I didn’t know the founder of DBT had that background.
FWIW, people with conditions like PTSD and BPD have far higher rates of smoking cigarettes than the general public. A big reason is because cigarettes contain nicotine, and nicotine activates the parasympathetic nervous system so it helps them regulate their nervous system.
Using electricity to stimulate the vagus nerve through things like tragus stimulation or a vagal implant can also increase activity of the PNS. Those are used for various mental health conditions.