Emerging Trends: Novel Molecular Targets and Moving Beyond Acute Symptoms in Bipolar Depression

Depression is the predominant phase of bipolar illness, but it still represents the greatest unmet need for the treatment of this condition. Few agents are approved to treat bipolar depression, and research into long-term treatment is lacking, especially for patients whose index episode is depression. Drugs commonly used to treat bipolar depression include antidepressants, antipsychotics, and mood stabilizers, but many of these agents are ineffective or have the potential to cause intolerable or serious side effects. Investigators looking for new treatments are exploring numerous molecular therapeutic targets. Some of these targets are familiar, such as dopamine agonism and glutamatergic modulation, but others are novel, such as protein kinase C regulation or melatonin agonism. Potential new agents hold promise for improving the treatment of not only acute depressive episodes but also long-term maintenance treatment of bipolar disorder.