The study will consist of a screening period, an open label solriamfetol treatment period, a double-blind randomized withdrawal period, and a follow-up period. Eligible subjects will be treated with open-label solriamfetol and monitored for clinical response. Subjects achieving clinical response will be randomized into the double-blind randomized withdrawal period in a 1:1 ratio to either continued treatment with solriamfetol or to switch to placebo, for the remainder of the double-blind period or until they experience relapse of depressive symptoms.