Brexpiprazole as Adjunctive Therapy in Adults With Major Depressive Disorder

Inclusion Criteria:

• Male and female participants (outpatients) between the regional age of majority (18 or 19 years of age) to 65 years of age, inclusive, at the time of informed consent.
• Primary diagnosis of MDD and in a current non-psychotic major depressive episode (MDE)as defined by Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria, who have been outpatients for at least 4 weeks, and have aninadequate response, per investigator judgment, to 1 or 2 adequate treatments of ADTsin their current MDE, including current ADT.
• Participants with a Patient Health Questionnaire 9-item scale (PHQ-9) ≥ 15 at thescreening and baseline visits, if separate.

Exclusion Criteria:

• Participants currently or previously treated with brexpiprazole including participantswho received brexpiprazole in any prior clinical trial.
• Participants with a concurrent DSM-5 diagnosis of the following will be excluded:
• Schizophrenia or schizoaffective disorder
• Bipolar I or bipolar II disorder
• Post-traumatic stress disorder
• Dementia
• Eating disorder
• Borderline personality disorder
• Antisocial personality disorder
• Participants with a suicidality score of 3 based on Inventory of DepressiveSymptomatology Self-Report (IDS-SR) suicidality item 18 or participants who, in theopinion of the investigator, presents a serious risk of suicide.