Platelet 5-HT2A receptor subresponsivity and lethality of attempted suicide in depressed in-patients

Abstract

In depressed patients, high-lethality suicidal acts are accompanied by serotonin system abnormalities analogous to those seen in completed suicides. We have previously reported greater platelet 5-HT2A receptor density, and impaired serotonin enhancement of ADP-induced platelet aggregation, an indirect measure of signal transduction, in high-lethality suicide attempters. We hypothesized that serotonin-activated phosphoinositide (PI) hydrolysis, a direct measure of platelet serotonin 5-HT2A receptor responsivity would be lower in depressed high-lethality suicide attempters. Twenty-three depressed in-patients that had previously made suicide attempts (low-lethality, n=6; high-lethality, n=17) h..