A Long-Term Study of Brexpiprazole in Patients With Major Depressive Disorder

Inclusion Criteria: * Rollover subjects 1. Outpatients 2. Subjects who have completed the double-blind period of the double-blind trial and can commence the treatment period of this trial within 28 days from the completionof the double-blind period of the double-blind trial 3. Subjects who have a level of comprehension sufficient to allow them to give written informed consent to all of the observation/examination/evaluation items specified in the protocol, and who can understand the contents of the trial 4. Subjects with a DSM-5 classification-based diagnosis of "major depressive disorder, single episode" or "major depressive disorder, recurrent episode" * New subjects 1. Outpatients 2. Male and female patients ≥ 65 years of age (at the time of informed consent) 3. Subjects who have a level of comprehension sufficient to allow them to give written informed consent to all of the observation/examination/evaluation items specified in the protocol, and who can understand the contents of the trial 4. Patients with a DSM-5 classification-based diagnosis of "major depressive disorder, single episode" or "major depressive disorder, recurrent episode" whose current episode has persisted for at least 8 weeks Exclusion Criteria: * Rollover subjects 1. Female subjects who are pregnant or breastfeeding or who have positive pregnancy test (urine) results at baseline 2. Sexually active male subjects or sexually active female subjects of childbearing potential, who will not agree to practice 2 different methods of birth control or to remain abstinent during the trial and for 30 days after the final IMP administration. For birth control, 2 of the following methods must be used: vasectomy, tubal ligation, vaginal diaphragm, intra-uterine contraceptive device (IUD), oral contraceptives, or condom with spermicide. 3. Subjects who experience a change to the manic state in the antidepressant treatment period of the double-blind trial 4. Subjects who are discovered to not meet the inclusion criteria or to fall under any of the exclusion criteria in the doubleblind trial 5. Subjects who showed marked noncompliance with the IMP treatment in the double-blind trial (subjects whose IMP compliance rates are \< 65% between prescribed visits) * New subjects 1. Sexually active male subjects who will not agree to practice 2different methods of birth control or to remain abstinent during the trial and for 30 days after the final IMP administration. For birth control, 2 of the following methods must be used: vasectomy, tubal ligation, vaginal diaphragm, intra-uterine contraceptive device (IUD), oral contraceptives, or condom with spermicide. 2. Patients with a treatment history showing that all antidepressants (also including those not used for the current major depressive episode) cannot be tolerated 3. Patients with a history of electroconvulsive therapy 4. Patients with a diagnosis of any of the following diseases according to DSM-5 1. Neurocognitive disorders 2. Schizophrenia spectrum and other psychotic disorders 3. Bipolar and related disorders 4. Feeding and eating disorders 5. Obsessive-compulsive disorder 6. Panic disorder 7. Posttraumatic stress disorder