We are not excluding comorbid anxiety disorders. Exclusion of patients with comorbid anxiety disorders would affect the generalizability of our findings since a substantial percentage of patients with major depression have these comorbid diagnoses. Instead, we will exclude patients with this comorbid diagnosis only if it is believed to be of clinical significance. Allowing participation by patients with histories of comorbid anxiety disorders broadens the inclusion criteria to more closely approximate patients seen in real world settings.