In this article, starting with brief introduction about depression, followed by mechanism and side effects of antidepressants widely use these days. After explaining glutamate hypothesis which applicated to newly developed antidepressant, describes the mechanism, efficacy, side effects of each newly developed antidepressants(NMDA (N-methyl D-asparate) receptor antagonists, subunit specific NMDA receptor antagonists, NMDA partial agonists, Glutamate release inhibitors, Metabotropic glutamate receptor antagonist).