Study to Evaluate Potential Predictors of Relapse in Participants With Major Depressive Disorder (MDD)

This is a prospective, multicenter, longitudinal, single-cohort, observational study in participants with MDD who have responded to, and are continuing to respond to and receive, an oral antidepressant treatment regimen. The study will consist of 2 parts: a screening phase of up to 2 weeks, and an observational phase of variable duration.