The human mind and body can be addicted to just about anything
that causes our body and mind to release the various peptides
that our body needs. If you get to much of one kind your body
adjusts to accept more of that kind and less of the others in affect
making you want more and more of that one peptide. This is what
happens when someone abuse's drugs because most drugs mimic
our natural chemicals.This is also why we have adrenaline junkies
and workaholics and the like.