Psilocybin is a rapid-acting antidepressant, but its mechanism of action in major depressive disorder remains unclear. In this secondary analysis of randomized, placebo-controlled trial with multimodal CSF and blood biomarker measurements, psilocybin selectively reduced CSF galanin and noradrenaline, implicating that normalization of these co-transmitters is a key pharmacodynamic signature.
Lysergic acid diethylamide (LSD) and the 5‐hydroxytryptamine (5‐HT) precursor, 5‐hydroxytryptophan produced similar functional effects in rat spinal cord and brain to the 5‐hydroxytryptamine precursor 5‐hydroxytryptophan, which indicates that LSD stimulates central 5‐HT receptors. By means of combined histochemical and biochemical techniques it was found that LSD reduced the turnover rate of...