Patients suffering from treatment-resistant depression (TRD) often do not remit from standard treatments. Currently, there is a specific treatment option available for these patients – intranasal esketamine, an enantiomer of ketamine. Meanwhil...

Treatment-resistant depression (TRD), a subset of major depressive disorder (MDD), presents a significant challenge to both the patients for its disabling impairment and physicians for undermined treatment effect. 1 Even though several definitions a...