Escitalopram is a selective serotonin (5-HT) reuptake inhibitor (SSRI) and the (S) isomer of citalopram and (R)-citalopram. It selectively binds to SERT (K = 0.89 nM) over the norepinephrine and dopamine transporters (Ks = >10,000 and 8,150 nM, respectively) and inhibits 5-HT reuptake in rat brain synaptosomes (IC = 2.1 nM). Escitalopram reduces immobility in the forced swim test in mice (ED = 12 mg/kg), indicating anti-depressant-like activity, and increases exploratory behavior in the black-and-white box test in mice with a minimal effective dose (MED) of 0.49 mg/kg, indicating anxiolytic-like activity. Escitalopram (20 µM) prevents acid sphingomyelinase activation and subsequent ceramide release induced by infection with replication-deficient vesicular stomatitis virus pseudoviral particles (pp-VSV) presenting the severe acute respiratory coronavirus 2 (SARS-CoV-2) spike protein in Vero cells, an effect that can be overcome with exogenous application of C16 ceramide . Formulations containing escitalopram have been used in the treatment of major depressive disorder (MDD) and generalized anxiety disorder (GAD).