Letters to the Editor
June 2002

Improvement of Cognitive Dysfunction After Treatment With Second-Generation Antipsychotics

Author Affiliations

Copyright 2002 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.2002

Arch Gen Psychiatry. 2002;59(6):572-573. doi:

Dr Purdon and colleagues should be commended on their efforts to study the highly important issue of long-term cognitive changes when patients with schizophrenia are treated with different antipsychotic drugs.1 Their report raises many issues that we discuss in this letter.

In addition to assessing psychopathology, all patients were studied using a neuropsychological test battery measuring cognitive functions in 6 domains (motor skills, attention, verbal fluency and reasoning, nonverbal fluency and construction, executive skills, and immediate recall). From these 6 domains, the authors computed a general cognitive index. They conclude that olanzapine has statistically significant advantages over both risperidone and haloperidol in the general cognitive index. All statistically significant differences between groups with regard to the 6 domains of cognitive functions fell victim to an α correction for multiple testing. In a within-group analysis, olanzapine showed significant advantages in only 1 of 6 specific cognitive domains (immediate recall) and in 1 of 17 individual tests.

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