Are hormones psychoactive? Evoked potential investigations in man

The somatosensory evoked potential (SEP) of physically and mentally healthy male subjects was recorded before as well as 4 hours after administration of one single dose of placebo, cyproterone acetate (an antiandrogen), and mesterolone (an androgen). Quantitative evaluation of drug-induced changes in SEP latencies and amplitudes, which, when plotted in terms of t-values, result in the so-called "SEP profiles", did not demonstrate any significant alterations after placebo. Contrary to this, cyproterone acetate induced systematic and significant changes characterized by a latency increase in the early peaks and latency decrease in the late peaks of the SEP. Apart from the non-significant amplitude changes, such alterations were previously described by us as typical for drugs of the anxiolytic class. Mesterolone on the other hand, produced a significant latency decrease in the early part and a latency increase in the late part of the evoked response which was found to be typical for the SEP profiles of tricyclic antidepressants. The amplitude did not show any systematic changes. Based on step-wise discriminant analysis of these data we could significantly differentiate both hormones from placebo as well as from each other. A comparative analysis of low and high doses did not yield any significant differences between the two levels. It was concluded that both test substances have psychoactive properties; whereas cyproterone acetate reveals anxiolytic qualities, mesterolone exhibits antidepressant ones. These findings are discussed from the clinical as well as from the neurophysiological point of view.