P300 and the thought disorder factor extracted by factor-analytic procedures in schizophrenia.
BACKGROUND
In order to clarify the clinical significance of P300 as a biologic marker that can reflect schizophrenic symptomatology, many previous studies have evaluated the relationship of P300 with the symptoms on the basis of a positive/negative dichotomy, but yielded inconsistent conclusions. Such a dichotomy has been criticized as being too reductionistic. Recently, most studies with factor-analytic procedures have extracted some symptom factors outside this dichotomy. Therefore, it is important to examine associations of P300 with the symptom factors extracted by these statistical analyses.


METHODS
In the present study, the amplitudes of P300 were measured by using an auditory oddball paradigm for 73 schizophrenics whose psychopathology was assessed with the Positive and Negative Syndrome Scale (PANSS).


RESULTS
The principal component analysis of the PANSS items revealed five factors labeled the thought disorder, negative, hostile/excitable, delusional/hallucinatory, and depressive factors. The score for the thought disorder factor correlated negatively with the amplitude of P300 recorded at Pz T5, and T6, but that for the other factors did not.


CONCLUSIONS
These findings suggest that the reduction of P300 amplitudes recorded at the midline parietal and bilateral temporoparietal regions may be one of the electrophysiologic indices representing the thought disorder clinically observed in schizophrenia.
Higashima
M
M
Department of Neuropsychiatry, School of Medicine, Kanazawa University, Japan.
Urata
K
K
Kawasaki
Y
Y
Maeda
Y
Y
Sakai
N
N
Mizukoshi
C
C
Nagasawa
T
T
Kamiya
T
T
Yamaguchi
N
N
Koshino
Y
Y
D000161:Acoustic Stimulation; D000328:Adult; D015415:Biomarkers; D003072:Cognition Disorders / Q000175:diagnosis; D003702:Delusions / Q000175:diagnosis; D004569:Electroencephalography / Q000706:statistics & numerical data; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D005163:Factor Analysis, Statistical; D005260:Female; D006212:Hallucinations / Q000175:diagnosis; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index
D015415:Biomarkers