Gonadal hormones and antihormones, serotonin and mood

Gonadal hormones influence activity of several monoaminergic neurotransmitters, and this might be one of the mechanisms by which these hormones are involved in modulation of behavior. Gonadal hormones' levels and mood fluctuate along the normal menstrual cycle; therefore, this might provide a model for the study of the interaction among hormones, mood, and other biochemical variables. The administration of gonadal hormones' antagonists ("antihormones") and the study of their central nervous system (CNS) and behavioral consequences may further elucidate hormonal-neurotransmitter interaction. We have studied several aspects of the serotonergic system along the menstrual cycle. Results show that imipramine receptor-binding in platelets is decreased in women with premenstrual dysphoric changes in the early luteal phase, 5 to 7 days before development of symptoms and shortly after the substantial periovulatory changes in gonadal hormones. The cortisol and prolactin responses to tryptophan were blunted during the late luteal phase compared with the midfollicular phase, and the cortisol, but not prolactin, responses to the serotonergic agonist 1-(m-chlorophenyl) piperazine, (mCPP) was also blunted during that period. An altered postsynaptic serotonergic responsivity might be suggested in these cases. The role of ovulation and gonadal hormones is further demonstrated by the elimination of dysphoric symptoms by the ovulation suppressant danazol.