title: A pharmaco-EEG study on antipsychotic drugs in healthy volunteers.
abstract: BACKGROUND
  Both psychotropic drugs and mental disorders have typical signatures in quantitative electroencephalography (EEG). Previous studies found that some psychotropic drugs had EEG effects opposite to the EEG effects of the mental disorders treated with these drugs (key-lock principle).
  
  
  OBJECTIVE
  We performed a placebo-controlled pharmaco-EEG study on two conventional antipsychotics (chlorpromazine and haloperidol) and four atypical antipsychotics (olanzapine, perospirone, quetiapine, and risperidone) in healthy volunteers. We investigated differences between conventional and atypical drug effects and whether the drug effects were compatible with the key-lock principle.
  
  
  METHODS
  Fourteen subjects underwent seven EEG recording sessions, one for each drug (dosage equivalent of 1 mg haloperidol). In a time-domain analysis, we quantified the EEG by identifying clusters of transiently stable EEG topographies (microstates). Frequency-domain analysis used absolute power across electrodes and the location of the center of gravity (centroid) of the spatial distribution of power in different frequency bands.
  
  
  RESULTS
  Perospirone increased duration of a microstate class typically shortened in schizophrenics. Haloperidol increased mean microstate duration of all classes, increased alpha 1 and beta 1 power, and tended to shift the beta 1 centroid posterior. Quetiapine decreased alpha 1 power and shifted the centroid anterior in both alpha bands. Olanzapine shifted the centroid anterior in alpha 2 and beta 1.
  
  
  CONCLUSIONS
  The increased microstate duration under perospirone and haloperidol was opposite to effects previously reported in schizophrenic patients, suggesting a key-lock mechanism. The opposite centroid changes induced by olanzapine and quetiapine compared to haloperidol might characterize the difference between conventional and atypical antipsychotics.
authors.affiliation: Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, Bern, Switzerland. yoshimum@takii.kmu.ac.jp
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Thomas
authors.initials: T
authors.lastname: Koenig
authors.forename: Satoshi
authors.initials: S
authors.lastname: Irisawa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Isotani
authors.forename: Keizo
authors.initials: K
authors.lastname: Yamada
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Gaku
authors.initials: G
authors.lastname: Okugawa
authors.forename: Takami
authors.initials: T
authors.lastname: Yagyu
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Werner
authors.initials: W
authors.lastname: Strik
authors.forename: Thomas
authors.initials: T
authors.lastname: Dierks
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001569:Benzodiazepines / Q000494:pharmacology; D002746:Chlorpromazine / Q000494:pharmacology; D018592:Cross-Over Studies; D003987:Dibenzothiazepines / Q000494:pharmacology; D004569:Electroencephalography / Q000187:drug effects*; D005583:Fourier Analysis; D006220:Haloperidol / Q000494:pharmacology; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D054833:Isoindoles; D008297:Male; D000077152:Olanzapine; D000069348:Quetiapine Fumarate; D012016:Reference Values; D018967:Risperidone / Q000494:pharmacology; D016037:Single-Blind Method; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors
chemical_list: D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D007211:Indoles; D054833:Isoindoles; D013844:Thiazoles; D001569:Benzodiazepines; D000069348:Quetiapine Fumarate; D006220:Haloperidol; D018967:Risperidone; C065533:perospirone; D000077152:Olanzapine; D002746:Chlorpromazine