Major Depression Clinical Trials

• Meet diagnostic and statistical manual of mental disorders-5th edition (DSM-5) diagnostic criteria for major depressive disorder (MDD), without psychotic features based upon clinical assessment

• Experienced at least one MDD episode prior to their current episode

• Current episode of MDD must be a minimum of 2 weeks in duration

• Must meet one of the following criteria regarding current medication status.

‣ Can be presenting for a new episode of MDD on no antidepressant treatment; however, must have been treated with an antidepressant medication in a prior episode for a minimum of 6 weeks at a stable dose at or above the minimum therapeutic level (medical record/source document).

‣ OR

⁃ Have taken up to two antidepressant treatments started in the current episode that were stopped (withdrawn), or will be withdrawn (washed out) due to inadequate response or intolerance.

• Body Mass Index (BMI) between 18 and 40 kilograms per square meter (kg/m\^2)

• Must be medically stable on the basis of the following performed at screening and double-blind (DB) baseline: physical examination (including a brief neurological examination), vital signs (including blood pressure), and 12-lead electrocardiogram (ECG)