The future of psychopharmacology of depression.

There are clear limitations to the currently approved pharmacotherapies of depression, including the fact that they are all essentially monoamine-based, have modest efficacy and a relatively slow onset of efficacy, and suffer from significant tolerability issues, particularly in the long term, including sexual dysfunction, weight gain, and cognitive impairments. This article reviews some of the most promising novel mechanisms that are not represented in compounds currently approved for depression in either the United States or Europe and that may represent the future of the psychopharmacologic treatment of depression, potentially addressing some of the efficacy and tolerability issues of antidepressants on the market. These potential antidepressant treatments include the multimodal serotonergic agents, the triple uptake inhibitors, the neurokinin-based novel therapies, the glutamatergic treatments, the nicotinic receptor-based treatments, the neurogenesis-based treatments, and antiglucocorticoid therapies. Some of these mechanisms appear to be more advanced in terms of drug development than others, but they all contribute to the global effort to develop more effective and better tolerated treatments for major depressive disorder.