Surveys used to conduct this study will be administered via telephone or online by InfoMedics, Inc., a company with a system for developing such patient-physician feedback programs. Participating physicians will ask their patients to participate in the program after Deplin® has been prescribed and provide them with a brochure containing an introduction to the program and instructions on how to enroll. Patients self-enroll, take a brief survey before starting their Deplin® prescription, and then a follow-up survey after 90 days of treatment with Deplin®. As patients complete surveys within the study, their physician will receive individualized feedback reports outlining their patient's treatment experience and progress. Patients will also receive a copy of their own reports, to help encourage them to continue taking Deplin® as directed. Patients will also receive educational materials about managing their depression.