The most pressing unmet need in the major depressive disorder (MDD) market is for the development of products with better efficacy, although there hasn’t been a major depression-drug breakthrough in nearly three decades. It is estimated that approximately 30% of MDD patients, termed treatment-resistant (TRD), do not respond to currently available treatment options. There is a great unmet need in terms of new treatments with novel mechanisms of action to treat patients who do not benefit from standard-of-care therapies, such as antidepressants.

The biggest development for this indication has been the research into ketamine as a breakthrough treatment for depression and a promising drug for TRD. Two major pharmaceutical companies, Janssen (part of Johnson & Johnson) and Allergan, are developing new medicines based on ketamine: esketamine (Janssen) and rapastinel (Allergan).