Tangentially, is the following accurate: it was my understanding (based on reading and very limited clinical exposure) that in BPD attempting suicide is a goal-oriented behavior, without intent to end their lives but rather to achieve personal or social goals (e.g. SO tries to leave them, they make a suicide attempt, SO is guilted into coming back). And that while they are at significant risk of completing suicide that outcome is generally accidental, such as a method more lethal than anticipated or delay in discovery/medical care.
While parasuicidal behaviors in BPD probably can be analyzed as playing a functional role in some sense (e.g. a really dysfunctional bid for attachment) and in some circumstances, this idea that BPD suicide attempts are "not serious" is very pernicious. The SI is very real and the proportion of people who meet criteria for BPD who ultimately kill themselves is pretty high (depending on estimates, ~10%, which you will note is not that much lower than more "severe" mental illnesses).
You do, however, need to separate out suicide attempts from impulsive self-harming behaviors that have some outward resemblance to a suicide attempt. When someone swallows six tylenol impulsively or ten Vistaril, this should probably not be thought of as a suicide attempt. If they finish the bottle, even if we know that the particular substance is unlikely to be lethal in overdose, that's a different question.
To work with this population effectively you simply have to accept that there is a very good chance that any given patient might complete suicide. If you are not okay with that, I would definitely refer out if at all possible, because changing that is a very long and involved process.
Now here's a problem I never was able to figure out. What if the person really has severe BPD, are chronically suicidal for real (in severe BPD they really could be severely suicidal). So what to do then? Especially if they're stuck into a facility where there's no DBT offered?
I've seen it happen and I hate it.
Here's how you do it:
"Patient X is at chronically elevated risk for self-injury as a result of [list the many, many risk factors that are not directly addressed by being locked on a psych ward]. Unfortunately the nature of their condition requires intensive and specialized psychotherapeutic interventions over a prolonged period of time that are simply unavailable in an inpatient setting. The treatment options that are available to us in an acute inpatient setting are highly unlikely to modify these risk factors. There is significant reason to believe that continued hospitalization will be countertherapeutic, and indeed since being admitted the patient has demonstrated this by [insert the regressive behaviors that have probably taken place at this point]. There is a serious and substantial risk of iatrogenic harm should we continue to hospitalize Patient X, and in the setting of minimal expected benefits for continued inpatient hospitalization, we feel that psychiatric discharge is imperative at this time. It is unfortunately the case that there remains a substantial chance that Patient X will self-injure again in the future, but short of incarceration for life, at this time we cannot prevent this. Patient X will need to develop the ability to tolerate their distress in the community and they will not able to develop these skills while in an acute locked inpatient setting. We expect that Patient X will seek hospitalization again in the future and will target brief hospitalizations for acute crisis management only to avoid further iatrogenic harm. Aftercare was arranged with _, crisis resources were provided and discussed with patient, safety plan was completed, blahblahblah"
