title: Relationship between negative symptoms in chronic schizophrenia and neuroleptic dose, plasma levels and side effects.
abstract: 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.
authors.affiliation: Department of Psychiatry, University of Toronto, Ontario, Canada.
authors.forename: L A
authors.initials: LA
authors.lastname: Tugg
authors.forename: D
authors.initials: D
authors.lastname: Desai
authors.forename: P
authors.initials: P
authors.lastname: Prendergast
authors.forename: G
authors.initials: G
authors.lastname: Remington
authors.forename: K
authors.initials: K
authors.lastname: Reed
authors.forename: R B
authors.initials: RB
authors.lastname: Zipursky
mesh_terms: D000328:Adult; D000368:Aged; D017109:Akathisia, Drug-Induced / Q000097:blood / Q000175:diagnosis; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D002908:Chronic Disease; D003863:Depression / Q000097:blood / Q000188:drug therapy* / Q000523:psychology; D003937:Diagnosis, Differential; D004305:Dose-Response Relationship, Drug; D004409:Dyskinesia, Drug-Induced / Q000097:blood / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000187:drug effects; D010302:Parkinson Disease, Secondary / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy*; D012565:Schizophrenic Psychology
chemical_list: D014150:Antipsychotic Agents