Autonomic nervous system activity and psychiatric severity in schizophrenia.
OBJECTIVE
Schizophrenia patients have a mortality rate two to three-fold higher than that of the general population. Despite the disorder's widespread recognition, how and to what extent autonomic nervous system (ANS) activity contributes to schizophrenia remains inconclusive. The aim of the present study, therefore, was to determine the extent of ANS activity depression with respect to healthy, well-matched control subjects and the severity of psychiatric disorders as determined using the Global Assessment of Functioning (GAF) scale among schizophrenia patients with special reference to antipsychotic dose.


METHODS
This study included 71 schizophrenia patients and 72 healthy controls. ANS activity was assessed by means of heart rate variability power spectral analysis.


RESULTS
ANS-related spectral parameters were three-four-fold lower in the patients compared to the control group (P < 0.01). Furthermore, when the patients without cardiovascular complications were classified according to GAF score, overall ANS (P = 0.033) and parasympathetic nervous system (PNS) activity (P = 0.025) were significantly reduced in the low-GAF as compared to the high-GAF group. Partial correlation analyses demonstrated that ANS activity was significantly correlated with GAF score while statistically eliminating the effects of age, gender, body mass index, antipsychotic dose, and lipid profiles of the patient population.


CONCLUSIONS
The significantly lower ANS activity in the low-GAF group suggests that such autonomic functional depression could be associated with the severity of schizophrenia. The present data further imply that schizophrenia patients with more depressed overall ANS and PNS activity might encounter increasing risks for cardiovascular events such as sudden death.
Fujibayashi
Mami
M
Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan.
Matsumoto
Tamaki
T
Kishida
Ikuko
I
Kimura
Tetsuya
T
Ishii
Chie
C
Ishii
Norio
N
Moritani
Toshio
T
D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use; D001341:Autonomic Nervous System / Q000503:physiopathology; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis* / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000209:etiology; D004562:Electrocardiography / Q000706:statistics & numerical data; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology*; D012720:Severity of Illness Index; D013564:Sympathetic Nervous System / Q000503:physiopathology
D014150:Antipsychotic Agents