Zombie Girl

The process described by Davis was an initial state of death-like suspended animation, followed by re-awakening—typically after being buried—into a psychotic state. The psychosis induced by the drug and psychological trauma was hypothesised by Davis to re-inforce culturally-learned beliefs and to cause the individual to reconstruct their identity as that of a zombie, since they "knew" they were dead, and had no other role to play in the Haitian society. Societal reinforcement of the belief was hypothesized by Davis to confirm for the zombie individual the zombie state, and such individuals were known to hang around in graveyards, exhibiting attitudes of low affect.
Davis' claim has been criticized, particularly the suggestion that Haitian witch doctors can keep “zombies” in a state of pharmacologically induced trance for many years. Symptoms of TTX poisoning range from numbness and nausea to paralysis (particularly of the muscles of the diaphragm), unconsciousness, and death, but do not include a stiffened gait or a death-like trance. According to psychologist Terence Hines, the scientific community dismisses tetrodotoxin as the cause of this state, and Davis' assessment of the nature of the reports of Haitian zombies is viewed as overly credulous.
Scottish psychiatrist R. D. Laing highlighted the link between social and cultural expectations and compulsion, in the context of schizophrenia and other mental illness, suggesting that schizogenesis may account for some of the psychological aspects of zombification.