One of his top ten "modern examples from the pharmacopoeia of dangerous delights" in fiction, as shared at the Guardian:
Substance D (A Scanner Darkly by Philip K Dick)Read about the other entries on the list.
Dick is perhaps the most prolific of the drug inventors. He used it as plot generator, a source of transformative energy – and a way to both escape reality and experience it more fully. He certainly put in the research in his own life, spending whole weeks off his head. Still, the books were written. Substance D is a psychoactive; it produces an initial euphoria, which is great until the user finds out what the D stands for: Despair, Desertion, Dumbness, and in its final incarnation, Death. Here lies the dark realism at the heart of Dick’s visionary craziness.
--Marshal Zeringue