Acute Efficacy of 20 Psychotropic Drugs on Human EEG Power Spectrum Variables Shown by Multivariate and Univariate Statistics

ABSTRACT The acute efficacy of single oral dosages of 20 psychotropic drugs, 5 neuroleptics, 5 anxiolytics, 5 antidepressants and 5 psychostimulants plus 5 placebos has been tested in 5 basic studies simultaneously designed and performed and involving 75 healthy male volunteers. Each study was done in a Latin square double-blind design with 15 subjects, each receiving one placebo and one compound of each of the four clinical therapeutic psychotropic drug classes. Three 5-minute EEG recordings (pre, 1 hr. and 3 hr. post drug intake) are taken to represent the drug effects. The differences in drug efficacy were tested by multivariate analysis of variance using 3 × 7 power spectrum estimates selected from these 3 EEG recordings. 14 of the 20 substances could be distinguished from placebo at a 5%, 16 at a 10% level. In order to demonstrate the results visually, examples of the mean relative power estimates as well as the standard q-score profiles of the 7 variables at three times are given. All 7 variables selected contribute to the differences between the drugs. However, some variables seem to be more specific for a defined drug class than others:υ = 5.5 – 8.5 Hz for the neuroleptics, β 1 F = 12.0 – 18.0 Hz for the anxiolytics, α 1 F = 8.5 – 10.5 Hz for the psychostimulants and a combination of δF = 1.5 – 3.5 Hz, l F and α 1 F for the antidepressants.