Double-blind comparisons of a selective serotonin reuptake inhibitor, zimelidine, and placebo on quantified EEG parameters and psychological variables.

A double-blind crossover comparison of three different single doses of a selective serotonin reuptake inhibitor, zimelidine, and a placebo on quantified EEG parameters and psychological variables was carried out in ten healthy male volunteers. Each subject randomly received 100 mg, 200 mg and 300 mg of zimelidine as well as placebo. C4--P4, P4--O2, C3--P3, P3--O1 and Fz--O1 EEG samples were taken by means of collodium Ag/AgCl stick on electrodes. 3 min average Fast Fourier Transformation power spectra based on 5 sec epochs were established. Additionally, performance tests and a subjective self-rating were carried out. The measurements, performed according to a strictly controlled schedule, were repeated 1, 2, 4 and 6 h post baseline (i.e. 8 a.m.). The data analysis was performed by means of two-way variance analysis for repeated measurements. Administration of three different single oral doses of zimelidine was found to significantly stabilize the average vigilance behaviour in terms of reduced slow wave EEG activity and of increased monorhythmic alpha activity. Simultaneously, concentration ability was improved and mild feelings of activation were reported. The results are discussed in the light of biochemical aspects and with regard to neurophysiological vigilance concepts.