Cocaine-induced psychosis and schizophrenia.The Problem
You are working in an emergency department. A patient presents in an acutely psychotic state, but his urine drug screen is positive for cocaine. You have no prior records or knowledge of the patient.
Is it possible to differentiate between cocaine-induced psychosis and schizophrenia?
We performed a Medline search combining cocaine and "psychotic, psychosis, delusion, or hallucination hallucination, false perception characterized by a distortion of real sensory stimuli. Common types of hallucination are auditory, i.e., hearing voices or noises and visual, i.e., seeing people that are not actually present. ."
Patients in inpatient rehabilitation for uncomplicated cocaine dependence were asked about a spectrum of cocaine effects (Neuropsychopharmacology 1997;16:77-82). Although the sample size was unknown, researchers in a follow-up study found that about one-half of the patients in the sample developed brief paranoid delusional episodes that were intense enough to influence their behavior. For example, these patients checked locks, hid, or armed themselves (Am. J. Addict. 2004;13:305-15).
Nineteen patients with amphetamine- or cocaine-induced psychosis were recruited from a psychiatric emergency service. Interviews occurred, on average, 58 hours after last drug use (Am. J. Addict. 2000;9:28-37). Patients were evaluated, in part, using the Positive and Negative Syndrome Scale (PANSS PANSS Positive & Negative Symptom Scale, see there ). Positive symptoms corresponded to the 95th percentile of schizophrenic norms, and negative symptoms corresponded to the 17th percentile. The thought disturbance and anergia An`er´gi`a
n. 1. Lack of energy; inactivity. symptom clusters corresponded to the 80th and 25th percentiles, respectively. All subjects had paranoid delusions; 89% had referential delusions, 53% had grandiose delusions, 32% had somatic delusions, 95% had bizarre delusions, 95% had auditory hallucinations, 68% had visual hallucinations, 26% had tactile hallucinations, 26% had olfactory olfactory /ol·fac·to·ry/ (ol-fak´ter-e) pertaining to the sense of smell.
Of, relating to, or contributing to the sense of smell. hallucinations, and 63% had Schneiderian forms of hallucination (such as hearing running commentary or two or more voices conversing with each other). One patient had gustatory gus·ta·to·ry or gus·ta·tive
Of or relating to the sense of taste. hallucinations.
In another study, 54 patients with schizophrenia without current substance abuse (SZ), 30 cocaine-abusing patients without schizophrenia (CA), and 32 cocaine-abusing schizophrenia patients (CA+SZ) were selected from patients entering psychiatric emergency services emergency services Emergency care '…services …necessary to prevent death or serious impairment of health and, because of the danger to life or health, require the use of the most accessible hospital available and equipped to furnish those services' at Bellevue Hospital in New York New York, state, United States
New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of (Schizophr. Bull. 1999:25:387-94). Subjects were evaluated, in part, using the Schedule for the Assessment of Positive Symptoms (SAPS) and Schedule for the Assessment of Negative Symptoms (SANS).
In a comparison of SAPS scores, the ratio of the SZ group's mean total to the CA group's was 2.2:1, with the presence of thought disorder in the SZ group accounting for most of the difference (4.3:1). The ratio of the two groups' mean total SANS scores was 1.6:1, with the presence of alogia and flat affect accounting for most of the difference (2.0:1 and 1.4:1, respectively).
Over a 2-year period, 988 patients were examined at an inpatient psychiatric unit in New York (Schizophr. Bull. 1997;23:187-93). Study subjects suffered with either substance-induced psychosis (about 50% of these subjects used cocaine) or schizophrenia. The authors found that formal thought disorder and bizarre delusions significantly predicted the diagnosis of schizophrenia (odds ratios of 3.55:1 and 6.09:1, respectively).
Psychotic phenomenology phenomenology, modern school of philosophy founded by Edmund Husserl. Its influence extended throughout Europe and was particularly important to the early development of existentialism. was compared between 35 cocaine-dependent patients and 16 acutely psychotic schizophrenia patients who had not abused substances within the past year (Clin. Neuropharmacol. 1994;17:359-69). The authors found that certain first-rank Schneiderian symptoms were more commonly observed in patients with schizophrenia, including delusions of control and thought broadcasting. Thought insertion and thought withdrawal were not experienced in this sample of cocaine-dependent patients, but were experienced by patients suffering with schizophrenia.
The subjective psychotic phenomena of 18 patients who had recently used cocaine and 18 patients with schizophrenia were compared in another study (Psychopathology psychopathology /psy·cho·pa·thol·o·gy/ (-pah-thol´ah-je)
1. the branch of medicine dealing with the causes and processes of mental disorders.
2. abnormal, maladaptive behavior or mental activity. 1992;25:71-8). The authors found that certain phenomena--such as increased intensity of colors, increased vividness of objects, macropsia, micropsia, and transient paranoia--were specific to the cocaine-induced psychotic state.
Investigators examined the experience of cocaine-induced psychosis in 55 individuals diagnosed with cocaine dependence (J. Clin. Psychiatry 1991;52:509-12). Subjects with primary psychotic disorders were excluded. Of these 55 patients, 90% experienced transient paranoid delusions, mostly directly related to drug use (such as delusions of being followed or surrounded by law-enforcement personnel or by people wanting to steal their drugs); 83% experienced auditory hallucinations, which is often consistent with paranoid delusions; 38% experienced visual hallucinations (such as people following them or looking in windows); 21% experienced tactile hallucinations (such as bugs or foreign objects on the skin); and 27% experienced transient behavioral stereotypies. Only 3 of 55 subjects reported delusions or hallucinations that were not specifically about drug use.
Many of these studies were limited by sample size, but the available evidence challenges the notion that cocaine-induced psychosis is indistinguishable from schizophrenia.
DR. LEARD-HANSSON is a forensic psychiatrist affiliated with Atascadero (Calif.) State Hospital. DR. GUTTMACHER is chief of psychiatry at the Rochester (N.Y.) Psychiatric Center. They can be reached at email@example.com.
BY JAN LEARD-HANSSON, M.D.
BY LAURENCE GUTTMACHER, M.D.