What's this new drug you speak of?
The sap from the Sleeping Tree. You can take it and it makes everything all purple looking. Its the only drug in the game that has any effects on what your character sees. Its pretty cool, plus it has a fortify health of 100 effect. My Khajiit takes a dose of it before bedtime, and a shot of Skooma in the morning to wake up.
And, from what Ysolda told me, I think its a reference to the first Elder Scrolls novel as well.