[Are you prepared for a lecture? Because you're getting one.]
The creation of zombies was for a long time explained by the use of a mixture of two powders - a potent neurotoxin called tetrodotoxin commonly found in pufferfish, and a dissociative drug such as datura which combined would induce a death-like state. That theory has since then been discredited, and more recent studies seem to point towards a link between social and cultural expectations and compulsion. Scottish psychiatrist R.D. Lang suggested that some of the characteristics of zombiefication are symptoms of schizophrenia rather than a chemically induced state of living death.