In a given year, an estimated 20.9 million American adults suffer from depressive disorder or depression. Without treatment, symptoms associated with these disorders can last for years, or can eventually lead to death by suicide or other causes. Fortunately, many people can improve through treatment with appropriate medications.

According to the American Psychiatric Association, successful treatment of patients with major depressive disorder is promoted by a thorough assessment of the patient and adherence to treatment plans. Treatment consists of an acute phase, during which remission is induced; a continuation phase, during which remission is preserved; and a maintenance phase, during which the patient is protected against the recurrence of a subsequent major depressive disorder.

This two part measure, therefore, looks at:

• The percentage of members with major depression who were initiated on an antidepressant drug and who received an adequate acute phase trial of medications (3 months).
• The percentage of members with major depression who were initiated on an antidepressant drug and who completed a period of continuous medication treatment (6 months).