Honore de Balzac was dependent on caffeine for his creative output

Honoré de Balzac depended on coffee. Not just a small amount, but huge amounts ingested daily.

As a result of taking so much coffee he had epic battles going on in his imagination. He felt his ideas were moving at superspeed in comparison to everyone else who was not on coffee, that he felt they were like motionless figures on a train platform as he sped by them in a blur of caffeine induced impatience.

"I have discovered a horrible, rather brutal method that I recommend only to men of excessive vigor. It is a question of using finely pulverized, dense coffee, cold and anhydrous, consumed on an empty stomach. This coffee falls into your stomach, a sack whose velvety interior is lined with tapestries of suckers and papillae. The coffee finds nothing else in the sack, and so it attacks these delicate and voluptuous linings . . . sparks shoot all the way up to the brain."