In comparison with control and drug-naïve depressed patients, citalopram-treated patients had significantly lower 5-HT Levels, While Drug-naïve patients had similar 5-HT platelet concentrations as controls.
Consistent with clinical results, the platelet 5-HT level decreased in chronic unpredictable mild stress (CUMS) citalopram-treated rats, in comparison with control and drug-naive CUMS rats.
CUMS+saline rats had high 5-HT level in hippocampus.
The levels of platelet 5-HT did not correlate with neuronal 5-HT levels.
Platelet 5-HT could response to SSRI treatment.