What is the primary use of Esketamine?

Esketamine is primarily used for treatment-resistant depression. This means that it is specifically indicated for patients who have not responded adequately to other antidepressant therapies. Esketamine is a derivative of ketamine, which has been recognized for its rapid antidepressant effects, particularly for individuals who do not find relief from traditional treatments. Administered as a nasal spray in this context, it acts on the NMDA receptor in the brain, leading to a quick alleviation of depressive symptoms in those who have been suffering from chronic depression despite other forms of treatment.

The other options do not align with the primary use of Esketamine. While anxiety disorders, insomnia, and PTSD may all be addressed through various pharmacological approaches, Esketamine's approval and clinical use are distinctly focused on those with treatment-resistant depression, highlighting its unique role in mental health treatment.