 The current standard for diagnosing MDD is the Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition - Text Revision DSM-IV-TR, which was published in 2000 by the American Psychiatric Association. The diagnosis is made based on an interview between the patient and physician in which nine criteria are assessed, including depressed mood, anhedonia, weight loss or gain, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue, feelings of worthlessness or guilt, difficulty concentrating, and recurrent thoughts of death. In patients with cancer, the diagnosis of MDD is more often based on anhedonia and feelings of worthlessness, as depressed mood, weight fluctuation, and sleep disturbance can be symptoms of the underlying cancer itself. Once the diagnosis has been made, there are several tools which have been created and validated for the purpose of assessing the severity of depression and for following the severity over time. The tool we intend to use in this study is the PHQ-9. 