Method of treating major depressive disorder

1. 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.

2. The method of claim 1 , wherein the antidepressant is selected from the group consisting of mono-amine oxidase inhibitors, tricyclic antidepressants, serotonin specific reuptake inhibitors, serotonin noradrenergic reuptake inhibitors, noradrenaline reuptake inhibitor, Kava-Kava, St. John's Wort, s-adenosylmethionine, imipramine, amitriptyline, desipramine, nortriptyline, doxepin, protriptyline, trimipramine, maprotiline, amoxapine, trazodone, bupropion, chlomipramine, fluoxetine, citalopram, escitalopram, sertraline, paroxetine, tianeptine, agomelatine, nefazadone, venlafaxine, desvenlafaxine, vilazodone, vortioxetine, duloxetine, reboxetine, mirtazapine, mianserin, phenelzine, tranylcypromine and moclobemide.

3. The method of claim 1 , wherein the esketamine is esketamine hydrochloride.

4. The method of claim 1 , wherein the reduction in the symptoms of major depressive disorder (MDD) is further measured by a reduction in the Montgomery-Åsberg Depression Rating Scale (MADRS) score after at least 14 days of administration of the oral dosage form.

5. The method of claim 1 , wherein the reduction in the symptoms of major depressive disorder (MDD) is further measured by a reduction in the Symptoms of Depression Questionnaire (SDQ) score as compared to baseline after at least 28 days of administration of the oral dosage form.

6. The method of claim 1 , wherein the reduction in the symptoms of major depressive disorder (MDD) is further measured by a reduction in the Sheehan Disability Scale (SDS) as compared to baseline after at least 28 days of administration of the oral dosage form.

7. The method of claim 1 , wherein the reduction in the symptoms of major depressive disorder (MDD) is further measured by a reduction in the Clinical Global Impression-Severity (CGI-S) score as compared to baseline after at least 28 days of administration of the oral dosage form.

8. The method of claim 1 , wherein the reduction in the symptoms of major depressive disorder (MDD) is measured by a reduction in the Montgomery-Åsberg Depression Rating Scale (MADRS) score as compared to baseline.

9. The method of claim 1 , wherein prior to the administration, the human patient has not responded to adequate doses and treatment durations of antidepressants other than ketamine or esketamine.

10. The method of claim 1 , wherein prior to the administration, the human patient has failed to demonstrate an improvement of up to 25% in the Montgomery-Åsberg Depression Rating Scale (MADRS) score after adequate doses and treatment durations of antidepressants other than ketamine or esketamine.

11. The method of claim 1 , wherein prior to the administration, the human patient has failed to demonstrate an improvement of up to 50% in the Montgomery-Åsberg Depression Rating Scale (MADRS) score after adequate doses and treatment durations of antidepressants other than ketamine or esketamine.

12. The method of claim 1 , wherein prior to the administration, the human patient has demonstrated an improvement of between 25 and 50% in the Montgomery-Åsberg Depression Rating Scale (MADRS) score after adequate doses and treatment durations of antidepressants other than ketamine or esketamine.

13. The method of claim 1 , wherein the administration of the oral dosage form is before the human patient goes to sleep.

14. The method of claim 1 , wherein the self-administration is in the human patient's own home.

15. The method of claim 1 , wherein following the administration of the oral dosage form, the patient is restricted from driving until the morning following the administration.

16. 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 esketamine Cmax of said administration is between 15 ng/mL and 30 ng/mL; and optionally, further comprising administering an additional antidepressant to the human patient.

17. The method of claim 16 , wherein the additional antidepressant is selected from the group consisting of fluoxetine, sertraline, paroxetine, citalopram, escitalopram, venlafaxine, desvenlafaxine, duloxetine, and fluvoxamine.