Improvement in cognitive function following a switch to ziprasidone from conventional antipsychotics, olanzapine, or risperidone in outpatients with schizophrenia.
OBJECTIVE
To assess changes in cognitive function in stable outpatients with schizophrenia switched to ziprasidone from conventional antipsychotics (n = 108), olanzapine (n = 104), or risperidone (n = 58) because of suboptimal efficacy or poor tolerability.


METHODS
In three separate 6-week trials, patients received ziprasidone 40 mg b.i.d. for 2 days, followed by 20-80 mg b.i.d. for the next 40 days. Before switching, and at endpoint, patients were evaluated with tests of working and secondary verbal memory, vigilance, visuomotor speed, verbal fluency, and executive functioning. Principal components factor analysis was performed to test for clustering of cognitive variables.


RESULTS
Significant improvements were seen at endpoint in secondary verbal memory (in all three groups), vigilance (in patients switched from conventional antipsychotics or risperidone), executive function (in patients switched from conventional antipsychotics or risperidone), and verbal fluency. Factor analysis on baseline scores suggested reduction of the cognitive variables to three factors: verbal skills, attention and short-term memory, and executive functioning. Analysis of z-transformed mean change in factor scores showed significant improvement in verbal skills and global score following the switch from conventional antipsychotics, olanzapine, or risperidone.


CONCLUSIONS
Patients requiring a change in antipsychotic therapy may exhibit cognitive improvement following a switch to ziprasidone.
Harvey
Philip D
PD
Mt. Sinai School of Medicine, New York University, 1425 Madison Avenue, Fourth Floor, New York, NY 10029, USA. philipdharvey1@cs.com
Meltzer
Herbert
H
Simpson
George M
GM
Potkin
Steven G
SG
Loebel
Antony
A
Siu
Cynthia
C
Romano
Steven J
SJ
D000293:Adolescent; D000328:Adult; D000553:Ambulatory Care; D001143:Arousal / Q000187:drug effects; D001288:Attention / Q000187:drug effects; D001569:Benzodiazepines / Q000008:administration & dosage / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects*; D004334:Drug Administration Schedule; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D000077152:Olanzapine; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D018967:Risperidone / Q000008:administration & dosage / Q000627:therapeutic use*; D012559:Schizophrenia / Q000188:drug therapy*; D013844:Thiazoles / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D014705:Verbal Behavior / Q000187:drug effects
D010879:Piperazines; D013844:Thiazoles; D001569:Benzodiazepines; C092292:ziprasidone; D018967:Risperidone; D000077152:Olanzapine