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

The introduction of atypical antipsychotics has created a renewed interest in adjunctive
therapy for MDD, particularly for treatment-resistant MDD. Several atypical antipsychotics
have been shown to enhance the response to ADT. This is a phase 3, multicenter, randomized,
double-blind, placebo-controlled, fixed-dose trial designed to assess the safety and efficacy
of brexpiprazole (2.0 mg/day) as adjunctive therapy to an assigned open-label ADT in
depressed subjects 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