Relationship between negative symptoms in chronic schizophrenia and neuroleptic dose, plasma levels and side effects

• Published in: Schizophrenia research Vol. 25; no. 1; pp. 71 - 78
• Main Authors: Tugg, Lome A., Desai, Devanshu, Prendergast, Peter, Remington Ken Reed, Gary, Zipursky, Robert B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 03.05.1997; Elsevier Science
• Subjects: Adult; Aged; Akathisia, Drug-Induced - blood; Akathisia, Drug-Induced - diagnosis; Antipsychotic Agents - administration & dosage; Antipsychotic Agents - adverse effects; Antipsychotic Agents - pharmacokinetics; Biological and medical sciences; Chronic Disease; Depression - blood; Depression - drug therapy; Depression - psychology; Diagnosis, Differential; Dose-Response Relationship, Drug; Dyskinesia, Drug-Induced - blood; Dyskinesia, Drug-Induced - diagnosis; Female; Humans; Male; Medical sciences; Middle Aged; Negative symptoms; Neuroleptics; Neurologic Examination - drug effects; Neuropharmacology; Parkinson Disease, Secondary - blood; Parkinson Disease, Secondary - chemically induced; Parkinson Disease, Secondary - diagnosis; Pharmacology. Drug treatments; Psychiatric Status Rating Scales; Psycholeptics: tranquillizer, neuroleptic; Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Schizophrenia; Schizophrenia - blood; Schizophrenia - drug therapy; Schizophrenic Psychology; Schizophrenia; Negative symptoms; Neuroleptics; Human; Psychosis; Symptomatology; Chronic; Neuroleptic; Psychotropic; Negative symptom; Toxicity; Differential diagnostic; Dose activity relation
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/S0920-9964(97)00009-1

The negative symptoms of schizophrenia are often difficult to distinguish from the side effects of antipsychotic medication. In this study, we tried to clarify this issue by studying a group of patients in a clinic setting where a wide range of antipsychotic doses were being prescribed. Thirty-one patients meeting DSM-III-R criteria for schizophrenia or schizoaffective disorder were studied. Clinical ratings were carried out to assess the positive and negative symptoms of schizophrenia, parkinsonism, akathisia and tardive dyskinesia. Plasma levels were also measured for the majority of patients. Antipsychotic plasma levels were found to be highly correlated with dose. Antipsychotic dose and plasma levels were not correlated with the severity of negative symptoms, akathisia or parkinsonism. However, the severity of positive symptoms and tardive dyskinesia were positively correlated with both dose and plasma level. These findings do not support the hypothesis that higher doses of antipsychotic medication are associated with more severe negative symptoms.