title: Influence of duration of untreated psychosis on auditory P300 in drug-naive and first-episode schizophrenia.
abstract: P300 amplitude reduction in schizophrenia is, according to previous studies, partially recovered by treatment with neuroleptics. However, whether this medication-induced P300 recovery is associated with duration of untreated psychosis (DUP) remains unreported; the present study is a preliminary examination of this question. Auditory P300 was recorded from 18 drug-naive and first-episode schizophrenia patients, among whom 10 were identified as short DUP, and eight as long DUP. Follow-up event-related potential tests were carried out after treatment with haloperidol or bromperidol for approximately 2 months. Recovery of P300 amplitude was replicated after neuroleptic medication was administered. A significant interaction was found between DUP and the medication effect in P300 amplitude over the left temporo-parietal area; a significant P300 recovery was seen in short DUP but not in long DUP. These results suggest that first-episode schizophrenia patients with long DUP might have severe impairments in the left temporal structures, supporting DUP as a key variable in future neurobiological studies of first-episode schizophrenia.
authors.affiliation: Shanghai Mental Health Center, 600 Wanping Road, Shanghai 20030, China. oukeigun@yahoo.com.cn
authors.forename: Jijun
authors.initials: J
authors.lastname: Wang
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hirayasu
authors.forename: Hiroto
authors.initials: H
authors.lastname: Hokama
authors.forename: Shin
authors.initials: S
authors.lastname: Tanaka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kondo
authors.forename: Mingdao
authors.initials: M
authors.lastname: Zhang
authors.forename: Zeping
authors.initials: Z
authors.lastname: Xiao
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013997:Time Factors
chemical_list: D014150:Antipsychotic Agents