Additional information on phencyclidine-related disorders
Additional Information on Phencyclidine-Related Disorders
Associated Features and Disorders
Associated descriptive features and mental disorders.
Although individuals with Phencyclidine Intoxication may remain alert and oriented, they may show delirium, coma, psychotic symptoms, or catatonic mutism with posturing. Repeated intoxications may lead to job, family, social, or legal problems. Violence, agitation, and bizarre behavior (e.g., confused wandering) may occur. Individuals with Phencyclidine Dependence or Abuse may report repeated intoxication-induced hospitalizations, emergency-room visits, and arrests for confused or bizarre behavior or for fighting. Conduct Disorder in adolescents and Antisocial Personality Disorder in adults may be associated with phencyclidine use. Dependence on other substances (especially cocaine, alcohol, and amphetamines) is common among those who have Phencyclidine Dependence.
Associated laboratory findings.
Phencyclidine (or a related substance) is present in the urine of individuals who are acutely intoxicated with one of these substances. The substance may be detectable in urine for several weeks after the end of prolonged or very high dose use because of its high lipid solubility. Phencyclidine may be detected more readily in acidic urine. Creatine phosphokinase (CPK) and serum glutamic-oxaloacetic transaminase (SGOT) are often elevated, reflecting muscle damage.
Associated physical examination findings and general medical conditions.
Phencyclidine Intoxication produces extensive cardiovascular and neurological (e.g., seizures, dystonias, dyskinesias, catalepsy, and hypothermia or hyperthermia) toxicity. Since almost half of individuals with Phencyclidine Intoxication present with nystagmus or elevated blood pressure, these physical signs can be useful in identifying a phencyclidine user. In those with Phencyclidine Dependence or Abuse, there may be physical evidence of injuries from accidents, fights, and falls. Needle tracks, hepatitis, human immunodeficiency virus (HIV) disease, and bacterial endocarditis may be found among the relatively few individuals who take phencyclidine intravenously. Drowning, even in small volumes of water, has been reported. Respiratory problems arise with apnea, bronchospasm, bronchorrhea, aspiration during coma, and hypersalivation. Rhabdomyolysis with renal impairment is seen in about 2% of individuals who seek emergency care. Cardiac arrest is a rare outcome.
Specific Culture, Age, and Gender Features
The prevalence of phencyclidine-related problems appears to be higher among males (about twofold), among those between ages 20 and 40 years, and among ethnic minorities (about twofold). Males compose about three-quarters of those with phencyclidine-related emergency-room visits.
Prevalence
Medical examiners nationally report that phencyclidine is involved in about 3% of deaths associated with substance use. It is mentioned as a problem in about 3% of substance-related emergency-room visits. According to a 1996 national survey of drug use in the United States, more than 3% of those age 12 and older acknowledged ever using phencyclidine, with 0.2% reporting use in the prior year. The highest lifetime prevalence was in those aged 26-34 years (4%), while the highest proportion using phencyclidine in the prior year (0.7%) was in those aged 12-17 years. It should be noted that because these surveys measured patterns of use rather than disorders, it is not known how many of those in the survey who used phencyclidine had symptoms that met criteria for Dependence or Abuse. The prevalence of Phencyclidine Dependence or Abuse in the general population is unknown.
Differential Diagnosis
For a general discussion of the differential diagnosis of Substance-Related Disorders, see p. 207. Phencyclidine-Induced Disorders may be characterized by symptoms (e.g., depressed mood) that resemble primary mental disorders (e.g., Major Depressive Disorder versus Phencyclidine-Induced Mood Disorder, With Depressive Features, With Onset During Intoxication). See p. 210 for a discussion of this differential diagnosis. Recurring episodes of psychotic or mood symptoms due to Phencyclidine Intoxication may mimic Schizophrenia or Mood Disorders. History or laboratory evidence of phencyclidine use establishes a role for the substance but does not rule out the co-occurrence of other primary mental disorders. Rapid onset of symptoms, presence of delirium, or observation of nystagmus or hypertension also suggests Phencyclidine Intoxication rather than Schizophrenia, but phencyclidine use may induce acute psychotic episodes in individuals with preexisting Schizophrenia. Rapid resolution of symptoms and the absence of a history of Schizophrenia may aid in this differentiation. Drug-related violence or impaired judgment may co-occur with, or may mimic aspects of, Conduct Disorder or Antisocial Personality Disorder. Absence of behavioral problems before the onset of substance use, or during abstinence, may help to clarify this differentiation.
Phencyclidine and related substances may produce perceptual disturbances (e.g., scintillating lights, perception of sounds, illusions, or formed visual images) that the person usually recognizes as resulting from the drug use. If reality testing remains intact and the person neither believes that the perceptions are real nor acts on them, the specifier With Perceptual Disturbances is noted for Phencyclidine Intoxication. If reality testing is impaired, the diagnosis of Phencyclidine-Induced Psychotic Disorder should be considered.
Differentiating Phencyclidine Intoxication from other Substance Intoxications (with which it often coexists) depends on a history of having taken the substance, the presence of characteristic findings (e.g., nystagmus and mild hypertension), and positive urine toxicological tests. Individuals who use phencyclidine often use other drugs as well, and comorbid Abuse or Dependence on other drugs must be considered. Phencyclidine Intoxication is distinguished from the other Phencyclidine-Induced Disorders (e.g., Phencyclidine-Induced Mood Disorder, With Onset During Intoxication) because the symptoms in these latter disorders are in excess of those usually associated with Phencyclidine Intoxication and are severe enough to warrant independent clinical attention.