A Research Study to Compare the Treatments of a Combination of Elzasonan With Zoloft, to Zoloft Alone, or Placebo in People With Major Depressive Disorder (MDD)

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Pfizer Investigational Site, Moscow

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Pfizer Investigational Site, Saint Petersburg

Pfizer Investigational Site, Saint Petersburg

Pfizer Investigational Site, Saint Petersburg

Pfizer Investigational Site, Saint Petersburg

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