Effects of olanzapine, risperidone and haloperidol on prepulse inhibition in schizophrenia patients: a double-blind, randomized controlled trial.
Prepulse inhibition (PPI), whereby the startle eyeblink response is inhibited by a relatively weak non-startling stimulus preceding the powerful startle eliciting stimulus, is a measure of sensorimotor gating and has been shown to be deficient in schizophrenia patients. There is considerable interest in whether conventional and/or atypical antipsychotic medications can "normalize" PPI deficits in schizophrenia patients. 51 schizophrenia patients participated in a randomized, double-blind controlled trial on the effects of three commonly-prescribed antipsychotic medications (risperidone, olanzapine, or haloperidol) on PPI, startle habituation, and startle reactivity. Patients were tested at baseline, Week 4 and Week 8. Mixed model regression analyses revealed that olanzapine significantly improved PPI from Week 4 to Week 8, and that at Week 8 patients receiving olanzapine produced significantly greater PPI than those receiving risperidone, but not haloperidol. There were no effects of medication on startle habituation or startle reactivity. These results support the conclusion that olanzapine effectively increased PPI in schizophrenia patients, but that risperidone and haloperidol had no such effects. The results are discussed in terms of animal models, neural substrates, and treatment implications.
Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA. jkwynn@ucla.edu
Jonathan K
JK
Wynn
Michael F
MF
Green
Joyce
J
Sprock
Gregory A
GA
Light
Clifford
C
Widmark
Christopher
C
Reist
Stephen
S
Erhart
Stephen R
SR
Marder
Jim
J
Mintz
David L
DL
Braff
D000161:Acoustic Stimulation; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000494:pharmacology / Q000627:therapeutic use; D004311:Double-Blind Method; D004576:Electromyography; D005260:Female; D006185:Habituation, Psychophysiologic / Q000187:drug effects*; D006220:Haloperidol / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D011618:Psychotic Disorders / Q000188:drug therapy / Q000523:psychology; D013216:Reflex, Startle / Q000187:drug effects*; D018967:Risperidone / Q000494:pharmacology / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D006220:Haloperidol; D018967:Risperidone; D000077152:Olanzapine