LY-2140023 is a methionine amide prodrug of the orthosteric metabotropic glutamate receptor (mGluR)2/3 agonist LY-404039, being developed by Eli Lilly & Co, for the potential oral treatment of schizophrenia. LY-404039 is a rigid glutamate analog that selectively binds to mGluR2/3 compared with all other glutamate receptors and transporters, and with other monoaminergic receptors that have been implicated in the therapeutic efficacy of atypical antipsychotic drugs. Activation of mGluR2 has been associated with the antipsychotic-like behavioral effects of LY-404039, as indicated by experiments using mGluR2-/- and mGluR3-/- mice. Furthermore, mGluR2 acts as a glutamatergic autoreceptor in the brain regions that are believed to be important in the pathophysiology of schizophrenia, such as the prefrontal cortex, striatum, hippocampal formation and the thalamus. The antipsychotic efficacy of LY-2140023, predicted by a common battery of preclinical behavioral screens for antipsychotic drugs, was confirmed in a randomized, placebo-controlled, phase II clinical trial in patients with schizophrenia. In addition, LY-2140023 lacked the extrapyramidal and metabolic side effects that are commonly observed with the majority of currently approved antipsychotic drugs. Thus, LY-2140023 represents a rare psychiatric medicine that demonstrates the promise of being rationally developed from bench to bedside.