title: Clozapine increases EEG photic driving in clinical responders.
abstract: Photically driven electroencephalography was tested in 17 chronic schizophrenia patients who were treated with clozapine for 5 weeks. Eight of the 17 patients showed clinical improvement on the Brief Psychiatric Rating Scale (delta BPRS > 30%) while the other 9 patients remained unchanged (delta BPRS < 15%). In comparison with the nonresponders, clozapine responders had a significantly greater increase in photic driving in the electroencephalogram (EEG), primarily in the low-frequency range of alpha band (7.2 hertz [Hz], 8.3 Hz, 9.0 Hz, and 9.6 Hz, but not 12.0 Hz). The difference in the resting EEG between the responders and nonresponders did not reach statistical significance. These findings suggested that EEG photic driving might be more sensitive than the resting EEG in detecting the central nervous system drug effect. Further analysis revealed that the increase of EEG photic driving was positively correlated with patients' clinical improvement. Combined with our previous observation in the drug-free schizophrenia patients who had lower EEG photic driving, present results supported the hypothesis that the amount of EEG alpha activity, particularly its synchronization to the external stimuli, could reflect the thalamic function in sensory information processing in schizophrenia.
authors.affiliation: Dept. of Psychiatry and Human Behavior, University of California, Irvine Medical Ctr., Orange 92668, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Jin
authors.forename: S G
authors.initials: SG
authors.lastname: Potkin
authors.forename: C
authors.initials: C
authors.lastname: Sandman
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000187:drug effects; D001143:Arousal / Q000187:drug effects* / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000503:physiopathology; D003024:Clozapine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects*; D005074:Evoked Potentials, Visual / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000188:drug therapy* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013788:Thalamus / Q000187:drug effects / Q000503:physiopathology
chemical_list: D003024:Clozapine