TY - JOUR
T1 - Comparison of cognitive performances during a placebo period and an atypical antipsychotic treatment period in schizophrenia
T2 - Critical examination of confounds
AU - Weickert, Thomas W.
AU - Goldberg, Terry E.
AU - Marenco, Stefano
AU - Bigelow, Llewellyn B.
AU - Egan, Michael F.
AU - Weinberger, Daniel R.
PY - 2003/8
Y1 - 2003/8
N2 - Although previous studies report cognitive improvement following atypical antipsychotic administration in schizophrenia (SC), few placebo-controlled within-subject studies with examination of confounds (symptom reduction, cooperation, learning, and outliers) have been reported. The present study examines the effects of atypicals and confounds upon cognition in SC. The hypothesis tested was that relative to placebo, atypicals as a general class of medication would elicit cognitive improvement in SC. In all, 19 patients with SC (15 males) completed the double-blind, counterbalanced, randomized within-subject study of the effects of atypical antipsychotics (risperidone, clozapine, olanzapine, or quetiapine) vs placebo administration upon cognitive performance in the domains of executive function, attention, memory, language, visual perception, and general intellect. Significant cognitive improvement during atypical antipsychotic administration relative to placebo withdrawal occurred in most cognitive domains with robust improvements in intelligence (p = 0.001), memory (p = 0.0009), and fluency (p < 0.002) even after outliers and unmotivated performances were excluded. These findings suggest that relative to placebo withdrawal, atypicals improve cognitive performance in SC. However, this finding may not be specific to atypicals, since analogous studies of typicals have not been performed.
AB - Although previous studies report cognitive improvement following atypical antipsychotic administration in schizophrenia (SC), few placebo-controlled within-subject studies with examination of confounds (symptom reduction, cooperation, learning, and outliers) have been reported. The present study examines the effects of atypicals and confounds upon cognition in SC. The hypothesis tested was that relative to placebo, atypicals as a general class of medication would elicit cognitive improvement in SC. In all, 19 patients with SC (15 males) completed the double-blind, counterbalanced, randomized within-subject study of the effects of atypical antipsychotics (risperidone, clozapine, olanzapine, or quetiapine) vs placebo administration upon cognitive performance in the domains of executive function, attention, memory, language, visual perception, and general intellect. Significant cognitive improvement during atypical antipsychotic administration relative to placebo withdrawal occurred in most cognitive domains with robust improvements in intelligence (p = 0.001), memory (p = 0.0009), and fluency (p < 0.002) even after outliers and unmotivated performances were excluded. These findings suggest that relative to placebo withdrawal, atypicals improve cognitive performance in SC. However, this finding may not be specific to atypicals, since analogous studies of typicals have not been performed.
KW - Antipsychotic agents
KW - Cognition
KW - Dopamine
KW - Learning
KW - Placebo
KW - Schizophrenia
UR - http://www.scopus.com/inward/record.url?scp=0042887005&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0042887005&partnerID=8YFLogxK
U2 - 10.1038/sj.npp.1300216
DO - 10.1038/sj.npp.1300216
M3 - Article
C2 - 12799617
AN - SCOPUS:0042887005
SN - 0893-133X
VL - 28
SP - 1491
EP - 1500
JO - Neuropsychopharmacology
JF - Neuropsychopharmacology
IS - 8
ER -