DEVELOPMENT OF A CLASSIFICATION RULE FOR 4 CLINICAL THERAPEUTIC PSYCHOTROPIC-DRUG CLASSES WITH EEG POWER-SPECTRUM VARIABLES OF HUMAN VOLUNTEERS

An objective rule for the classification of psychotropic substances has been developed. Classification is based on data from 5 basic studies simultaneously designed and performed and involving 75 healthy volunteers who ingested 20 different psychotropic drugs and 5 placebos in single oral dosages. Each volunteer took one psychostimulant, one antidepressant, one neuroleptic, one minor tranquilizer and one placebo in a double-blind Latin square cross-over design. The variables were 6 frequency bands, based on power spectrum estimates and determined by factor analysis, plus total power in the 1.5-30.0 Hz range. An objective classification rule was established by multi-group (5 groups) linear discriminant analysis. Reclassification of the substances by the new rule yielded correct results for 17 out of 20 psychotropic drugs and 4 out of 5 placebos. Of placebos from various studies not used for the establishment of the classification rule, 7 of 9 were classified correctly. The validity of the rule for other classes of substances will have to be verified in independent studies.