APA Dictionary of Psychology

a reversible syndrome due to the recent ingestion of phencycline (PCP) or a pharmacologically similar substance, included in DSM-IV-TR, DSM-5, and DSM-5-TR. It includes clinically significant behavioral or psychological changes (e.g., belligerence, assaultiveness, impulsiveness, unpredictability, psychomotor agitation, impaired judgment, impaired social or occupational functioning), as well as one or more signs of physiological involvement (e.g., vertical or horizontal nystagmus, hypertension or tachycardia, numbness or diminished responsiveness to pain, unsteady gait, unclear speech, muscle rigidity, seizures, coma). See also substance intoxication.