Endogenous Plasma Lithium Concentrations and Schizophrenia

Oh, Chae Keun; Kim, Jong In; Lee, Byung Hak; Yoon, Jae Hang; Kim, Chang Hyun; Kim, Seong Jae

Abstract

OBJECTIVES
The aim of this study was to compare endogenous plasma lithium concentrations among schizophrenic patients classified by DSM-IV subtype and control groups and to investigate the correlation of endogenous plasma lithium concentration and psychotic symptoms in schizophrenia.
METHODS
Schizophrenic patients were selected among psychiatric inpatients without lithium medication and then classified by DSM-IV schizophrenia subtype. Schizophrenic patient groups were composed of 15 disorganized type, 15 paranoid type and 15 undifferentiated type schizophrenic patients. The control group was composed of 15 healthy subjects without any psychiatric disease. Endogenous plasma lithium concentrations were estimated by inductively coupled plasma atomic emission spectrometer. The psychotic symptoms in schizophrenic patients were classified as positive symptoms, negative symptoms and disorganized symptoms according to andreasen classification1 about SANS and SAPS items. Endogenous plasma lithium concentration among three subtypes of schizophrenia and control group was compared, and correlation between endogenous plasma lithium concentrations and psychotic symptoms was examined.
RESULTS
1) Schizoprenic patients showed higher endogenous plasma lithium concentration than control groups (p=0.033). Endogenous plasma lithium concentrations were significantly different among three subtypes of schizophrenia (p=0.001). Compared with the control group, disorganized type showed higher endogenous plasma lithium concentration, but paranoid type and undifferentiated type were not significantly different. 2) Disorganized symptoms correlated with endogenous plasma lithium concentration (r=0.416, p=0.004), but negative symptom and positive symptom did not significantly correlate with endogenous plasma lithium concentration (r=0.202, p=0.184. r=-0.216, p=0.155).
CONCLUSION
These results suggested that schizophrenic patients with disorganized symptom show the differences in utilization or distribution of endogenous lithium.