The Selective Serotonin 5-HT_2A Receptor Agonist (<i>S</i>)-3-(2,5-Dimethoxy-4-(trifluoromethyl)phenyl)piperidine (LPH-5) Induces Persistent and Robust Antidepressant-Like Effects in Rodents

Psychedelics have emerged as a promising treatment for mental health disease, and the therapeutic potential of psilocybin and lysergic acid diethylamide (LSD) is presently being pursued in numerous clinical trials. This has prompted a search for novel agents with more specific pharmacological activities than the rather promiscuous classical psychedelics. Here we present the detailed pharmacological characterization of one such compound, LPH-5 [(<i>S</i>)-3-(2,5-dimethoxy-4-(trifluoromethyl)-phenyl)-piperidine]. LPH-5 was found to be a potent partial agonist at the 5-HT_2A receptor (5-HT_2AR) with pronounced selectivity for 5-HT_2AR over the related 5-HT_2BR and 5-HT_2CR in a range of functional assays. LPH-5 dose-dependently induced head-twitch responses (HTR) as well as robust acute and persistent antidepressant-like effects in rats. These results suggest that selective 5-HT_2AR activation holds antidepressant potential and indicate that this activity component is key for the therapeutics effects of classical psychedelics.