People who are highly driven usually don't spend much time sleeping, it is considered a waste of good energy. Can't really create too much when one is sleeping, so why go to sleep.
The down side is when sleep comes, it needs to be very deep, almost comma in order to get a really good rest. So there is a dance created, running from sleep then craving it to the point of using artificial means. The cycle is never ending, until we make the necessary changes.
In his case, it was serious drugs that needed the direction of a professional to administer it.
Sorry Mrs Jackson, you and your family have to come to terms with the fact that Michael took risks that killed himself with a doctor assisting in the process.
Greiveing is hard, but it's time to go through the process. We are all here to hold your hand, you have a world of support.