Substance D is the fictional drug at the center of the drama in Philip K. Dick's novel A Scanner Darkly. An amalgam of the recreational drugs popular when Dick was writing, it provides a vehicle for criticizing irresponsible drug use and drug prohibition.
The different symptoms of long term use of Substance D are presented in the descriptions of the different charcaters:
- Bob Arctor (Special Agent Fred): split personality and cross-chatter
- Jim Barris = homicidal mania
- Ernie Luckman = loss of independent will
- Charles Freck = formication (delusional parasitosis or Ekbom's syndrome)
- A Scanner Darkly 2006 film