The term dissociative comes from the Latin words dis (apart, away from each other) and associare (to gather, to unite). It translates loosely as 'a substance capable of evoking a loosening of associations'. The term dissociative is used to denote a class of the *hallucinogens characterized by the ability to reduce or block afferent signals to the conscious mind, especially those derivative of the sense organs. Some examples of dissociatives are ketamine, dextromorphan, nitrous oxide, and muscimol (derived from the mushroom Amanita muscaria). Dissociatives are believed to act via the biochemical pathway of VV-methyl D-aspartate (NMDA) receptor antagonism, and the inhibition of the action of glutamate within the CNS. It has been suggested that dissociatives evoke a pharmacologically induced state of * sensory deprivation, and a subsequently increased awareness of endogenous activity in the service of self-exploration, dreamlike activity, and hallucinatory activity. The mode of action of the primary dissociatives is thought to be similar to that of * phencyclidine (i.e. angel dust). The term dissociative is used in opposition to the terms *psychedelic and * deliriant, which refer to two additional classes of the group of hallucinogens. A person intentionally using a dissociative for the purpose of exploring the psyche may be called a *psychonaut.
References
Leuner, H. (1962). Die experimentelle Psychose. Ihre Psychopharmakologie, Phänomenologie und Dynamik in Beziehung zur Person. Berlin: Springer-Verlag.
Nichols, D.E. (2004). Hallucinogens. Pharmacology & Therapeutics, 101(2), 131-181.
Dictionary of Hallucinations. J.D. Blom. 2010.