Method of treating major depressive disorder

A method of treating major depressive disorder (MDD) in a human patient in need thereof consisting essentially of orally administering once daily to said patient for at least 28 days, an oral dosage form comprising esketamine;

• wherein the oral dosage form is self-administered by the human patient at night;
• wherein the esketamine Cmax of said administration is between 15 ng/mL and 30 ng/mL;
• wherein following said administration, the patient is restricted from driving for no more than eight hours;
• and wherein the human patient's symptoms of MDD are measured by the Montgomery-Asberg Depression Rating Scale (MADRS) score at at least day 28 of the treatment regimen and are reduced at at least day 28 of the treatment regimen as compared to placebo and optionally, further comprising administering an antidepressant, an antimanic agent or an anxiolytic drug.