The relationship of neuropsychological test performance with the PANSS in antipsychotic naïve, first-episode psychosis patients.
BACKGROUND
Chronic schizophrenia patients have been sampled for factor analytic studies to identify the factor structure of the Positive and Negative Syndrome Scale (PANSS). Many of these studies have identified a cognitive factor, which may provide useful information about patients for whom formal neuropsychological testing is unavailable. However, the relationship between the clinically rated cognitive factor and performance-based cognitive test scores has not been thoroughly examined, particularly in patients who are early in the course of illness.


OBJECTIVE
The validity of the PANSS cognitive factor was examined in a sample of antipsychotic naïve, first-episode psychosis patients and the PANSS items that best predicted cognitive functioning were identified.


METHODS
PANSS scores and performance on a battery of cognitive tests from the baseline assessment of a clinical trial of 167 neuroleptic naïve patients with schizophrenia-like illnesses were analyzed.


RESULTS
Factor analysis revealed a five-factor model that was consistent with previously described factor models from samples of chronically treated patients. There were modest correlations (less than r=0.44) between the derived cognitive factor and six of the neuropsychological test variables (Wisconsin Card Sorting Test total errors and number of categories correctly sorted, WMS-R immediate and delayed recall scores, Category Fluency total score, and WAIS-R digit symbol). Five PANSS items (P6, N5, N6, G2, and G10) were identified that predicted global cognitive functioning; however, 66% of the variance in cognitive functioning remained unexplained.


CONCLUSIONS
A PANSS cognitive factor can be identified in first-episode, neuroleptic naïve patients. However, clinical ratings of cognitive deficits lack sensitivity and specificity and thus should not be relied upon fully.
Good
Kimberley P
KP
Department of Psychiatry, Dalhousie University, Suite 9216-AJLB, 5909 Veterans Memorial Lane, Halifax, NS, Canada B3H 2E2. kimpgood@dal.ca
Rabinowitz
Jonathan
J
Whitehorn
David
D
Harvey
Philip D
PD
DeSmedt
Goedele
G
Kopala
Lili C
LC
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D002908:Chronic Disease; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D004311:Double-Blind Method; D005163:Factor Analysis, Statistical; D005260:Female; D006220:Haloperidol / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
D014150:Antipsychotic Agents; D006220:Haloperidol