EFFECTS OF SELECTIVE SEROTONIN REUPTAKE INHIBITORS ON PLATELET SEROTONIN PARAMETERS IN MAJOR DEPRESSIVE DISORDER

The effects of treatment with serotonin (5-HT) reuptake inhibitors on platelet 5-HT2 receptors, 5-HT reuptake sites and 5-HT uptake were stu died in a double-blind trial comparing two selective serotonin reuptak e inhibitors (SSRI), paroxetine, and fluoxetine, for the treatment of major depression, Hamilton Depression Rating Scale (HAM-D) scores and platelet 5-HT parameters were determined in 21 depressed patients at b aseline, after 4 and 8 weeks of treatment, and were compared to 21 hea lthy controls, Antidepressant treatment did not significantly alter th e density of 5-HT reuptake sites, labelled with [H-3]paroxetine, or 5- HT2 receptors, labelled with [H-3]LSD, However, a strong correlation w as observed between the HAM-D suicidality item and 5-HT2 receptor dens ity at baseline, A marked increase in platelet 5-HT2 receptors at base line was observed in suicidal depressed patients compared to those wit h no suicidal ideation and healthy controls, Changes in [H-3]paroxetin e Bmax and in [H-3] 5-HT uptake significantly correlated with change i n HAM-D score at 4 and 8 weeks respectively, These results confirm pre vious reports of an association between suicidality and platelet 5-HT2 receptor upregulation, Our data also fends support to the use of plat elet 5-HT parameters as indicators of antidepressant efficacy, particu larly in suicidal depressed patients. (C) 1997 Society of Biological P sychiatry