Adjunctive Mixed Salts Amphetamine for Depressed Adults With Incomplete Response to Current Antidepressant Therapy

Inclusion Criteria: 1. Male or female outpatients between the ages of 18-70. 2. Subject must meet criteria for single or recurrent, non-psychotic episode of MDD according to Diagnostic and Statistical Manual IV Text Revised (DSM-IV-TR) diagnosis, as determined by Structured Clinical Inventory of Depressive Symptoms (SCID) and confirmed by assessment of investigator. 3. Current depressive episode must be at least 8 weeks in duration. 4. Hamilton Depression Rating Scale 17 (HDRS-17) score ≥ 14 at both the screen and baseline visits. 5. Subject must have been receiving an adequate, stable dose of ADT, based on Massachusetts General Hospital-Antidepressant Treatment Response Questionnaire (MGH-ATRQ). 6. Subject must be responding inadequately to his/her current monotherapy ADT in the current major depressive episode (MDE). 7. Subjects must be able to read and understand English and be able to provide written informed consent. 8. Subjects must be considered reliable, able to comply with protocol requirements and understand the risks and benefits, per the investigator's clinical judgment. 9. Female subjects of childbearing potential must agree to use adequate form of birth control throughout the course of the study. \- Exclusion Criteria: 1. Inadequate response during the current episode to more than 3 adequate trials of an ADT, as defined by the MGH-ATRQ. 2. Psychiatric hospitalization within the last 6 months. 3. Presence of cognitive disorder(s), bipolar disorder, Axis II pathology or other condition that investigator believes would interfere with participation in the study. 4. Substance use disorder, current (as defined by DSM-IV-TR SCID) or positive results on urine drug screen or laboratory blood tests. 5. Risk to self or others. 6. The presence of any medical condition, current or past, stable or unstable, that contraindicates the use of antidepressant medication or mixed amphetamine salts medication as determined by clinician's judgment. 7. Clinically significant abnormal findings on physical exam, EKG or laboratory tests; current unstable, untreated hypertension in the opinion of the investigator; history of cerebrovascular accident (CVA) or seizure disorder (other than febrile childhood seizure). 8. Allergies and/or adverse drug reactions to MSA. 9. Failure to respond to an adequate trial of MSA adjunctive to ADT in the current episode. 10. Subjects taking narcotics, herbal/homeopathic remedies and/or other substance with psychotropic activity, based upon clinical judgment of study investigator. 11. Pregnant or breastfeeding women. \-