title: Reduction of auditory event-related P300 amplitude in subjects with at-risk mental state for schizophrenia.
abstract: Neurophysiological methods allow the examination of cognitive-cortical functioning in patients with schizophrenia in its prodromal states. As revealed by previous studies, event-related potential components such as auditory evoked P300 associated with cognitive processes, such as attention and orientation, are known to be reduced in amplitude in acute and chronic as well as in medicated and unmedicated patients. It is, however, unclear whether a P300 amplitude reduction occurs before the schizophrenic psychosis is fully manifested. We studied patients in the prodromal phase of the schizophrenic disorder (i.e. subjects with an at-risk mental state showing attenuated psychotic symptoms or brief limited intermittent symptoms) as well as first-episode patients and chronic patients with schizophrenia and compared these groups to healthy subjects. The event-related P300 was recorded during an auditory oddball paradigm. Groups differed significantly from each other in the P300 amplitude at Pz (F(3/149)=2.532, p=0.02). Post-hoc tests revealed significantly lower P300 amplitudes of non-medicated prodromal (p=.03), first-episode (p=.01) and chronic patients (p=.001) compared to the healthy controls. The study revealed that there are neurophysiological changes as the reduction in P300 amplitudes begins early in schizophrenia at the prodromal phase, i.e. before a manifestation of full-blown psychosis, and that these changes seem to have a progressive course from prodromal to chronic state of schizophrenia as assumed in this cross-sectional study.
authors.affiliation: Department of Psychiatry, Ruhr University Bochum, LWL University Hospital, Germany.
authors.forename: Seza
authors.initials: S
authors.lastname: Ozgürdal
authors.forename: Yehonala
authors.initials: Y
authors.lastname: Gudlowski
authors.forename: Henning
authors.initials: H
authors.lastname: Witthaus
authors.forename: Wolfram
authors.initials: W
authors.lastname: Kawohl
authors.forename: Idun
authors.initials: I
authors.lastname: Uhl
authors.forename: Marta
authors.initials: M
authors.lastname: Hauser
authors.forename: Inge
authors.initials: I
authors.lastname: Gorynia
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.forename: Martin
authors.initials: M
authors.lastname: Heinze
authors.forename: Andreas
authors.initials: A
authors.lastname: Heinz
authors.forename: Georg
authors.initials: G
authors.lastname: Juckel
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001288:Attention; D001931:Brain Mapping; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology; D035061:Control Groups; D003430:Cross-Sectional Studies; D004569:Electroencephalography / Q000706:statistics & numerical data; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology*; D012565:Schizophrenic Psychology