A friend from uni (years ago) said to me "You're not a writer unless you have ten cups of coffee a day." So, drugs and writing? Do they mix? Plenty of writers have been drug fiends, plenty of writers have been as straight as a freshly made arrow. As an alcoholic who recently fell off the wagon, I can say I've taken just about everything once or twice in my life and none of them mix well with writing. Under the influence, even only alcohol and/or caffeine I struggle to concentrate. My productivity goes down and my commitment wavers. But experiences with perception altering drugs most definitely generate experiences that are later applicable to writing. What about you? Caffeine, alcohol, prescription drugs, illicit drugs, sleep deprivation, even mental illness. Anything that alters your mental state. Do you find they help or hinder your writing? In a broad sense; both literally writing under the influence, and the experience itself contributing to you as a writer. EDIT: please do not make this a discussion about "how high you got last weekend." Or incriminate yourself. NSA man, that's a thing... well, not to me I'm in Australia, but I'm sure they're still watching.