MIK, to the best of my somewhat limited knowledge Mike's 'addiction' was not until after he competed (and lost) against Arnold down thar in Austrailia.
My personal belief is that Arnold's 'dominance' was part of the reason why Mike had somewhat of a downfall back then.
Someone who was somewhat more associated with Mike back then at that time might be able to speak more appropriately on that subject than I am able to do so.
In the meantime, I can do some asking around.