EFFECTS OF THE SEROTONIN RECEPTOR AGONIST SUMATRIPTAN, ON HORMONAL PLASMA-LEVELS IN HEALTHY AND DEPRESSED SUBJECTS - A PLACEBO-CONTROLLED STUDY

The effects of placebo and sumatriptan, a serotonin 5HT1-like receptor agonist, on prolactin (PRL), cortisol, TSH, and growth hormone (GH) p lasma levels were assessed in healthy and depressive female subjects, in order to study the participation of 5HT1 receptors in their release and possible differences between the groups. PRL, cortisol, and TSH d ecreased with time, both during placebo and drug administration (ANOVA R). The PRL decrease at 20 minutes was smaller during the drug trials, compared to placebo. For cortisol, there were significant group-time, and drug-group-time interactions. Post-hoc comparisons showed that th e drug caused larger cortisol reductions in the group of depressive su bjects compared to placebo and compared to healthy subjects. The reduc tions were significant first 40 min after administration, indicating a central action of the drug that diminishes serotonin release, possibl y by acting on presynaptic serotonin receptors which may be more sensi tive in depression. TSH was not influenced by the drug in either group , while the GH data were rather inconclusive. The results show partici pation of SHT1-like receptors in the PRL and cortisol releasing mechan isms, which seem to be more sensitive in depression.