in DSM–IV–TR and DSM–5, a reversible syndrome that develops over a short period of time (usually hours to days) following heavy consumption of phencycline (PCP) or a similar substance. It includes disturbances of consciousness (e.g., reduced ability to focus, sustain, or shift attention) accompanied by other changes in cognition (e.g., memory deficit, disorientation, language disturbance) in excess of those usually associated with phencyclidine intoxication. See also substance intoxication delirium.