Electrophysiological indices of automatic and controlled auditory information processing in first-episode, recent-onset and chronic schizophrenia.
BACKGROUND
Deficits in amplitudes of auditory event-related potentials (ERP) indexing preattentive, automatic (mismatch negativity, MMN) and controlled, attention-dependent (N2, P3) auditory information processing have been well described in chronic schizophrenia. Normal MMN, but deficient N2 and P3 have been reported in first-episode patients. No study has investigated these ERPs concurrently in first-episode patients; thus, reported differences in MMN, N2 and P3 generation may reflect differences in patient samples rather than genuine differences in abnormal generation of these ERPs.


METHODS
We recorded MMN, N2 and P3 in 26 first-episode patients, 25 recent-onset patients within 1.5 to 5 years after first admission, 25 chronic patients and 39 healthy controls.


RESULTS
Recent-onset and chronic, but not first-episode patients showed reduced MMN. However, among first-episode patients those with low premorbid educational achievement demonstrated significantly reduced MMN. All patient groups showed pronounced N2 deficits and, to a variable extent, abnormalities in P3 generation.


CONCLUSIONS
Abnormalities in N2 and P3 generation appear to reflect premorbid neuropathology, whereas MMN deficits may index both ongoing disease processes associated with illness progression as well as premorbid neurocognitive impairment. ERPs may provide tools to assess static and progressive neuropathology in schizophrenia. These findings need confirmation in longitudinal studies.
Umbricht
Daniel S G
DS
Exploratory Clinical Development, Translational Medicine, Novartis Pharma AG, Basel, Switzerland. daniel.umbricht@novartis.com
Bates
John A
JA
Lieberman
Jeffrey A
JA
Kane
John M
JM
Javitt
Daniel C
DC
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D002908:Chronic Disease; D003265:Contingent Negative Variation / Q000502:physiology*; D004522:Educational Status; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011930:Reaction Time / Q000502:physiology; D012189:Retrospective Studies; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013997:Time Factors