Theoretically it is possible since your brain keeps everything working in your body. If you gain enough control over your mind then you could theoretically shut off all the major processes in the brain such as the heart, thus dieing would occur.
don't worry, if somehow you held your breath long enough to black out, you would unconsciously start breathing again.
How do you think we were able to breathe after birth? I don't know about ya'll, but I didn't pop out of the womb and go "Okay, let's see.... breathe in... breathe out.... scream!"
Thank you :]
I think it is possible though. If there are people who can stop their hearts and stuff like that, they could probably stop their hearts long enough to die.
It all depends on how you would define "making yourself die"...