I think this theme is more psychological than chemical/physiological. Somebody codes just for enjoy, somebody codes just for money. And the most of coding people, including me, want both :)
Well, I am addictive on nicotine, and, probably, on caffeine (both java and tea). And on adrenaline, endorphine, enkefaline and other internal drugs too. And sometimes I am very drunk or stoned.
But I code with clear mind, mostly. This is good for concentration, invention, not attracting too divergent or crazy thinks. External chemistry can help a little bit in a special situations, but it is wrong way of life.