I wonder if some of it is brought on by the fact of being a rock star and whether it starts with the heavy touring that is needed to get to the top.
You're flying to new dates every day, back and forth through time zones, performing in front of 120dB SPL PA systems. Someone drags you off to meet city VIPs right after the concert where booze is plentiful, you're dragged back to the hotel and shot up with something to make you sleep, in the morning you need something to wake up....and on it goes.
My guess is that the weaker succumb to a need for something to push it all back, and then they're into a whole other problem.
ryck
"What Were Once Vices Are Now Habits" The Doobie Brothers
