The prevalence of phencyclidine use disorder is unknown. Approximately 2.5% of the pop- ulation reports having ever used phencyclidine. The proportion of users increases with age, from 0.3% of 12- to 17-year-olds, to 1.3% of 18- to 25-year-olds, to 2.9% of those age 26 years and older reporting ever using phencyclidine. There appears to have been an in— crease among 12th graders in both ever used (to 2.3% from 1.8%) and past-year use (to 1.3% from 1.0%) of phencyclidine. Past-year use of ketamine appears relatively stable among 12th graders (1.6%—1.7% over the past 3 years).
There is little information about risk factors for phencyclidine use disorder. Among indi- viduals admitted to substance abuse treatment, those for whom phencyclidine was the primary substance were younger than those admitted for other substance use, had lower educational levels, and were more likely to be located in the West and Northeast regions of the United States, compared with other admissions.
Ketamine use in youths ages 16—23 years has been reported to be more common among whites (0.5%) than among other ethnic groups (range 0%—0.3%). Among individuals ad— mitted to substance abuse treatment, those for whom phencyclidine was the primary sub- stance were predominantly black (49%) or Hispanic (29%).
Males make up about three-quarters of those with phencyclidine-related emergency room visits.
Laboratory testing may be useful, as phencyclidine is present in the urine in intoxicated in- dividuals up to 8 days after ingestion. The individual’s history, along with certain physical signs, such as nystagmus, analgesia and prominent hypertension, may aid in distinguish- ing the phencyclidine clinical picture from that of other hallucinogens.
Functional Consequences of Phencyclidine Use Disorder
In individuals with phencyclidine use disorder, there may be physical evidence of injuries from accidents, fights, and falls. Chronic use of phencyclidine may lead to deficits in mem- ory, speech, and cognition that may last for months. Cardiovascular and neurological tox- icities (e.g., seizures, dystonias, dyskinesias, catalepsy, hypothermia or hyperthermia) may result from intoxication with phencyclidine. Other consequences include intracranial hemorrhage, rhabdomyolysis, respiratory problems, and (occasionally) cardiac arrest.
Other substance use disorders. Distinguishing the effects of phencyclidine from those of other substances is important, since it may be a common additive to other substances (e.g., cannabis, cocaine).
Schizophrenia and other mental disorders. Some of the effects of phencyclidine and related substance use may resemble symptoms of other psychiatric disorders, such as psy- chosis (schizophrenia), low mood (major depressive disorder), violent aggressive be- haviors (conduct disorder, antisocial personality disorder). Discerning whether these behaviors occurred before the intake of the drug is important in the differentiation of acute drug effects from preexisting mental disorder. Phencyclidine-induced psychotic disorder should be considered when there is impaired reality testing in individuals experiencing disturbances in perception resulting from ingestion of phencyclidine.
A. A problematic pattern of hallucinogen (other than phencyclidine) use leading to clini- cally significant impairment or distress, as manifested by at least two of the following.
occurring within a 12-month period: 1. The hallucinogen is often taken in larger amounts or over a longer period than was intended.
2. There is a persistent desire or unsuccessful efforts to cut down or control halluci- nogen use.