I think the fact you think it's just in peoples' minds is in
your mind, n having climbed mountains, done various stimulants, had proper anxiety attacks and.... fucked myself up on mephedrone, I can most certainly say it was beyond a few psychological niggles from reading internet forums.
The low then high blood pressure, random chest pains, weird pressures through out the day on the left hand side of my chest... may have made me more aware of heartbeat and pulse rate, but they made me notice something which was different.
No idea quite what I did, and after about a month I did feel significantly better, but it kinda shook me up enough for a while. In the end i'm not concluding anything, as the night which "triggered" this involved drinking a shit ton along with the meph, and perhaps it would have happened anyway. All I know is i've never felt physical sensations around my chest/heart like that
ever before in my life, n it's enough for me to not want to push things too far.
Still, it's a rather nice drug and the vary majority seem to just get spannered and then feel fine. Exercising some caution with dosage would make sense tho.