Classical composers question?

Berlioz did opium regularly. His Symphonie Fantastique is actually program music based upon a dream he had on an opium trip.

The composers of the baroque and classical periods, most unlikely. A few of those of the Romantic period may have experimented, such as Berlioz; but "do some drugs", I seriously doubt it. But those of the neoclassical - the period between WW I and WW II, IF that's what you're referring to - very possible. But I don't "know" of any in particular. Alberich

who knows, probably opium if anything

Mozart was a heavy drinker, who wasn't in those days?

I highly doubt it

No way, shape or form. If you read the history of classical music and study the lives of these great composers, you'll realise that Bach was high on God, Beethoven was manic depressive and Mozart was a bit of a nutty genius. (See the movie Amadeus) With minor exceptions most great classical music composers were very unhappy geniuses, many of them died young often going crazy in their later years, and misunderstood and unappreciated in their lifetimes.

I don't know, but I doubt very much that those stuff would increase anyone's level of creativity. Haven't found any drunk who can carry a tune myself.

Mebbe, who knows?