1) I have observed over a hundred people with BPD traits among the several hundred I have interacted with in 12 Step programs like AA, NA, MA, ACA, CoDA, EA and SLAA over the past 30+ years.

2) I have observed 30 or 40 people with obvious BPD traits in SA treatment settings. 

3) I have (thus far) observed about 150 people in BPD treatment and other support group settings.
 
4) I have to say that while substance (ab)use may seem to "work" as a coping mechanism for the powerful emotions we feel, it doesn't work very well:

. . . a) Those who continue to use during treatment tend *very clearly* to be the ones who have the most difficulties and the highest drop-out rates. 

. . . b) The ones who use AA, NA, MA, etc., as a platform for *further* recovery -- and remain clean and sober -- tend to remain in treatment, participate effectively, understand concepts, utilize the therapeutic tools they are shown how to use, and improve *far* more rapidly. 

5) These are not *absolutes*, but the *tendencies* or "trends" are obvious.

6) I am *not* proselytizing for any 12 Step program. Just reporting what I have seen with my own eyes. 