I was on a length course of Doxycycline (for borreliosis). It had the side effect of acting as an antidepressant. I got better (from the borreliosis), the treatment ended, and so did the antidepressant effect. It may be a study of n=1 but antibiotics affect bacteria selectively, including gut bacteria. It could be that the H. pylori solution is pointing the way to greater things.
Hmm? The mechanism discussed here is the immune system attacking human cells during an immune response to strep. What do pills have to do with that, and do you mean antibiotics or do you mean psychiatric medications?