Efficacy and Safety of Brexpiprazole as Adjunctive Treatment in Elderly Patients With Major Depressive Disorder With an Inadequate Response to Antidepressant Treatment

Inclusion Criteria: * The patient is an outpatient consulting a psychiatrist. * The patient has a recurrent Major Depressive Disorder diagnosed according to DSM-IV-TR™. The current Major Depressive Episode (MDE) should be confirmed using the Mini International Neuropsychiatric Interview (MINI). * The patient had at least one previous MDE before the age of 60 years. * The patient has a moderate to severe depression and an insufficient response to at least one and no more than three adequate antidepressants treatments. * The patient, if a woman, must have had her last natural menstruation ≥24 months prior to the Screening Visit. * The patient, if a man, agrees to protocol-defined use of effective contraception if his female partner is of childbearing potential. Exclusion Criteria: * The patient has any current psychiatric disorder or Axis I disorder (DSM-IV-TR™ criteria), established as the primary diagnosis, other than MDD. * The patient has a current Axis II (DSM-IV-TR™) diagnosis of borderline, antisocial, paranoid, schizoid, schizotypical or histrionic personality disorder. * The patient has experienced/experiences hallucinations, delusions or any psychotic symptomatology in the current MDE. * The patient suffers from mental retardation, organic mental disorders, or mental disorders due to a general medical condition (DSM-IV-TR™ criteria). * The patient, in the opinion of the investigator, or according to Columbia Suicide Severity Rating Scale (C-SSRS), is at significant risk of suicide. * The patient has had neuroleptic malignant syndrome. * The patient has any relevant medical history or current presence of systemic disease. * The patient has a neurodegenerative disorder. * The patient has, at the Screening Visit an abnormal ECG that is, in the investigator's opinion, clinically significant. * The patient has a history of cancer, other than basal cell or Stage 1 squamous cell carcinoma of the skin, that has not been in remission for \>5 years prior to the first dose of IMP. * The patient is, in the investigator's opinion, unlikely to comply with the protocol or is unsuitable for any reason. Other inclusion and exclusion criteria may apply.