In order to examine the effects of risperidone on cognitive impairment in schizophrenia, event-related potentials (ERPs) were recorded before and after switching from conventional neuroleptics to risperidone in schizophrenic patients. ERPs were recorded during two auditory discrimination tasks (an oddball task and a distraction task) in 10 medicated schizophrenic patients during conventional neuroleptic and risperidone treatments. The amplitudes and latencies of N 100 and P 300 component were measured in ERPs for target stimuli in the oddball task and in ERPs for target and novel stimuli in the distraction task. Although N 100 amplitude and latency and P 300 amplitude did not change significantly after switching the drug compared to that during conventional neuroleptic treatment, P 300 latency for target stimuli shortened significantly during risperidone treatment in both tasks, accompanied by the shortening of the reaction time in the distraction task. The P 300 latency change did not correlate with the change of the severity of psychopathology. These findings suggest that risperidone may speed the information processing in schizophrenic patients, contributing to the improvement of cognitive functions.
References
1
Bellack A S, Gold J M, Buchanan R W.
Cognitive rehabilitation for schizophrenia: Problems, prospects, and strategies.
Schizophr Bull.
1999;
25
257-274
2
Meltzer H Y, McGurk S R.
The effects of clozapine, risperidone, and olanzapine on cognitive function in schizophrenia.
Schizophr Bull.
1999;
25
233-255
3
Lindstrom E, von Knorring L.
Changes in single symptoms and separate factors of the schizophrenic syndrome after treatment with risperidone or haloperidol.
Pharmacopsychiatry.
1994;
27
108-113
7
Iwanami A, Okajima Y, Kuwakado D, Isono H, Kasai K, Hata A. et al .
Event-related potentials and thought disorder in schizophrenia.
Schizophr. Res.
2000;
42
189-191
8
Egan M F, Duncan C C, Suddath R L, Kirch D G, Mirsky A F, Wyatt R J.
Event-related potential abnormalities correlate with structural brain alterations and clinical features in patients with chronic schizophrenia.
Schizophr Res.
1994;
11
259-271
9
Hegerl U, Juckel G, Muller-Schubert A, Pietzcker A, Gaebel W.
Schizophrenics with small P 300: a subgroup with a neurodevelopmental disturbance and a high risk for tardive dyskinesia?.
Acta Psychiatr Scand.
1995;
91
120-125
10
Iwanami A, Yamashina M, Kazamatsuri H, Kamijima K.
P 300 and disability of daily life in schizophrenia.
Prog Neuropsychopharmacol Biol Psychiatry.
1999;
23
423-430
11
Kasai K, Okazawa K, Nakagome K, Hiramatsu K, Hata A. et al .
Mismatch negativity and N 2b attenuation as an indicator for dysfunction of the preattentive and controlled processing for deviance detection in schizophrenia: a topographic event-related potential study.
Schizophr Res.
1999;
35
141-156
12
Iwanami A, Isono H, Okajima Y, Noda Y, Kamijima K.
Event-related potentials during a selective attention task with short interstimulus intervals in patients with schizophrenia.
J Psychiatry Neurosci.
1998;
23
45-50
13 American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Washington D. C American Psychiatric Association 1994
14 Spitzer R L, Endicott J. Schedule for affective disorders and schizophrenia. Lifetime version. New York, NY; Biometric Research, New York State Psychiatric Association 1978
15
Grillon C, Courchesne E, Ameli R, Geyer M A, Braff D L.
Increased distractibility in schizophrenic patients. Electrophysiologic and behavioral evidence.
Arch Gen Psychiatry.
1990;
47
171-179
17
Blackwood D H, Whalley L J, Christie J E, Blackburn I M, St. Clair D M, McInnes A.
Changes in auditory P 3 event-related potential in schizophrenia and depression.
Br J Psychiatry.
1987;
150
154-160
18
Faux S F, McCarley R W, Nestor P G, Shenton M E, Pollak S D, Penhune V. et al .
P 300 topographic asymmetries are present in non-medicated schizophrenics.
Electroencephalogr Clin Neurophysiol.
1993;
88
32-41
19
Roxborough H, Muir W J, Blackwood D H, Walker M T, Blackburn I M.
Neuropsychological and P 300 abnormalities in schizophrenics and their relatives.
Psychol Med.
1993;
23
305-314
20
Shajahan P M, O’Carroll R E, Glabus M F, Ebmeier K P, Blackwood D H.
Correlation of auditory „oddball” P 300 with verbal memory deficits in schizophrenia.
Psychol Med.
1997;
27
579-586
21
O’Donnell B F, Faux S F, McCarley R W, Kimble M O, Salisbury D F, Nestor P G, et a l. et al .
Increased rate of P 300 latency prolongation with age in schizophrenia. Electrophysiological evidence for a neurodegenerative process.
Arch Gen Psychiatry.
1995;
52
544-549
22
Salisbury D F, Shenton M E, Sherwood A R, Fischer I A, Yurgelun-Todd D A, Tohen M. et al .
First-episode schizophrenic psychosis differs from first-episode affective psychosis and controls in P 300 amplitude over left temporal lobe.
Arch Gen Psychiatry.
1998;
55
173-180
23
Pfefferbaum A, Ford J M, White P M, Roth W T.
P 3 in schizophrenia is affected by stimulus modality, response requirements, medication status, and negative symptoms.
Arch Gen Psychiatry.
1989;
46
1035-1044
24
Coburn K L, Shillcutt S D, Tucker K A, Estes K M, Brin F B, Merai P. et al .
P300 delay and attenuation in schizophrenia: reversal by neuroleptic medication.
Biol Psychiatry.
1998;
44
466-474
28
Duncan-Johnson C C, Donchin E.
The P 300 component of the event-related brain potential as an index of information processing.
Biol Psychology.
1982;
14
1-52
29
Umbricht D, Javitt D, Novak G, Bates J, Pollack S, Lieberman J. et al .
Effects of clozapine on auditory event-related potentials in schizophrenia.
Biol Psychiatry.
1998;
44
716-725
30
Kern R S, Green M F, Marshall J r.
BD, Wirshing WC, Wirshing D, McGurk S, et al. Risperidone vs. haloperidol on reaction time, manual dexterity, and motor learning in treatment-resistant schizophrenia patients.
Biol Psychiatry.
1998;
44
726-732
31
Rossi A, Mancini F, Stratta P, Mattei P, Gismondi R, Pozzi F. et al .
Risperidone, negative symptoms and cognitive deficit in schizophrenia: an open study.
Acta Psychiatr Scand.
1997;
95
40-43
32
Green M F, Marshall Jr B D, Wirshing W C, Ames D, Marder S R, McGurk S. et al .
Does risperidone improve verbal working memory in treatment-resistant schizophrenia?.
Am J Psychiatry.
1997;
154
799-804
33
Kern R S, Green M F, Marshall Jr B D, Wirshing W C, Wirshing D, McGurk S. et al .
Risperidone versus haloperidol on secondary memory: can newer medications aid learning?.
Schizophr Bull.
1999;
25
223-232
34
Honey G D, Bullmore E T, Soni W, Varatheesan M, Williams S CR, Sharma T.
Differences in frontal cortical activation by a working memory task after substitution of risperidone for typical antipsychotic drugs in patients with schizophrenia.
Proc Natl Acad Sci U.S.A..
1999;
96
13 432-13 437
36
Squires N K, Squires K C, Hillyard S A.
Two varieties of long-latency positive waves evoked by unpredictable auditory stimuli in man.
Electroencephalogr Clin Neurophysiol.
1975;
38
387-401
