Study of the Safety and Efficacy of Fixed-dose Brexpiprazole (OPC-34712) as Adjunctive Therapy in the Treatment of Adults With Major Depressive Disorder With and Without Anxious Distress

Inclusion Criteria: * Male and Female subjects between 18-65 years of age, with diagnosis of major depressive disorder with or without anxious distress * Current depressive episode must be at least 8 weeks in duration Exclusion Criteria: * Subjects with a history of Neuroleptic Malignant Syndrome or Serotonin Syndrome * Subjects who report an inadequate response to more than 3 antidepressant treatments in the current episode * Subjects with a current Axis I diagnosis of: Delirium, dementia, amnestic or other cognitive disorder, Schizophrenia, schizoaffective disorder, or other psychotic disorder, Bipolar I or II disorder