Esketamine for the treatment of depression

A method of treating major depressive disorder in a human patient in need thereof based on a dosing regimen, said regimen having an induction phase and, a subsequent maintenance phase, wherein the induction phase has a duration of 4 weeks, the method comprising:

• intranasally administering an aqueous formulation comprising esketamine and/or a pharmaceutically acceptable salt thereof in the induction phase to provide a therapeutically effective amount of about 56 mg or about 84 mg of esketamine per induction phase treatment session to the patient, wherein the induction phase treatment session occurs at a frequency of twice weekly during the induction phase;
• and
• intranasally administering an aqueous formulation comprising esketamine and/or a pharmaceutically acceptable salt thereof in the maintenance phase to provide a therapeutically effective amount of about 56 mg or about 84 mg of esketamine per maintenance phase treatment session to the patient, wherein the maintenance phase treatment session occurs at a frequency of once weekly or once every other week during the maintenance phase;
• and
• wherein the patient has a worsening of depression symptoms following a missed treatment session during the maintenance phase and is returned to a previously higher frequency of treatment session before the missed treatment session.