Hi verytired,
I actually had the EXACT questions you posted here (as my ex was downing an insane amount of energy drinks, coffee, alcohol and taking B12 injections), many months ago before I left my uBPDh so here are my thoughts: I have not yet read any solid evidence that offers a direct connection from those things you mentioned to BPD - BUT the reality is, stimulants (caffeine, sugar, B vitamins etc) and depressants (alcohol) will affect ANYONE's mood, so it only makes sense that a person who struggles with their own emotional instability, a pwBPD would be even more affected. It just makes sense. Knowing what I know now about BPD and my ex husband's substance abuse (I eventually discovered it extended FAR FAR beyond energy drinks, etc) I feel that the person with BPD is in such a state of constant inner turmoil that they feel forced to self medicate - which explains why so much research reports that BPD and drug abuse go hand in hand.
Long before I knew about BPD and the drug use, I tried for many years with futile efforts to thwart my husband's addictive nature toward the consumption of alcohol, energy drinks and the like. It was useless. The more I tried anything, the more I lost myself. Substances in all forms are their escapes from the irrational emotions and anxieties. Today I work on finding my own escape from the BPD world of chaos. May you find your own version of peace. Be well and stay in touch.
