An animal model is described which allows for differentiation of 8 common drug categories (antidepresssives, anticonvulsive, analgesic, neuroleptic, stimulant, narcotic, sedative and hallucinogenic drugs) by recording field potentials from stereotactically implanted electrodes and wireless transmission of the data. Four to five representatives of each drug category have been looked at in terms of changes of frequency content with respect to 6 different frequency ranges (delta, theta, alpha1, alpha2, beta1 and beta2). Basically all drugs within one category show a very similar pattern of changes providing a disease specific "fingerprint" of electrical activity. Discriminant analysis provides the statistical fundament for classification of single drugs into disease specific clusters. The data suggest that this type of analysis of the electrical activity of the brain not only allows for classification of unknown compounds but also can accelerate drug development to a major degree. Finally the recognition of new indications of already launched drugs not only becomes feasible but has resulted in filing of new indication patents.