Amendment #1 specifies the following changes to the original protocol MEM-MD-91, dated April 05, 2012: Increasing sample size from approximately 192 enrolled patients to approximately 800 to 900 enrolled patients. Rationale: The Number of Patients (Planned and Analyzed) section has been amended to change the planned sample size such that a sufficient number of patients can be enrolled in MEM-MD-68 from this lead-in study. The sample size of MEM-MD-68 has been increased based on the discussion with the FDA. In order to provide sufficient patients transitioning to a follow-up randomized withdrawal study (MEM-MD-68), approximately 800 to 900 patients will be enrolled into this study. Adding information regarding the Data Safety Monitoring Board (DSMB) Rationale: This section has been added to include information about the DSMB. No safety issue necessitated the use of the DSMB. An Ethics Committee requested that a DSMB be established. Clarifying if administration of the Columbia-Suicide Severity Rating Scale (C-SSRS) is appropriate given a patient’s developmental and/or situational status. Rationale: This section was revised to clarify if administration of the C-SSRS is appropriate given a patient’s developmental and/or situational status. All references to the Social Responsiveness Scale (SRS) Patient Autoscore version have been revised. Rational: The Social Responsiveness Scale (SRS) Patient Autoscore version has not been provided to the sites. The SRS total raw score should be calculated before the patient/caregiver leave the site. Immediate Reporting of Serious Adverse Events Rationale: This section was revised to indicate where the SAE Form fax number and Medical Emergency phone number for sites outside the United States and Canada can be found. Contact Information Rationale: Appendix II was revised to indicate where the contact information and Medical Emergency phone number for sites outside the United States and Canada can be found.