Percentage of patients 18 years of age and older who were treated with antidepressant medication, had a diagnosis of major depression, and who remained on an antidepressant medication treatment. Two rates are reported: a Percentage of patients who remained on an antidepressant medication for at least 84 days (12 weeks) b Percentage of patients who remained on an antidepressant medication for at least 180 days (6 months)