About 7.5% of all American adults suffered at least one depressive episode. Among those with depression who did not receive treatment, more than 43% said cost. A quarter (24%) saw a doctor but did not get this type of medication.

Less than two-thirds (64.5%) of those individuals got treated for their depression, the study found. A major depressive episode was defined as any period of two weeks or longer characterized by depressed mood, loss of pleasure or interest, and at least four other symptoms, such as loss of appetite, lack of sleep and poor self-image. The report, from the Substance Abuse and Mental Health Services Administration (SAMHSA), drew on data from the agency's 2007 National Survey on Drug Use and Health, involving approximately 45,000 non-institutionalized adults. 14.2% of Americans who described their health as "fair" or "poor" had a depressive episode, compared to 4.3% of those in self-described "excellent" health.Among people who did seek out help for their depression, many (68.8%) saw or talked to a medical doctor or other health professional and got a prescription medication for their illness.

Rates of major depressive episodes were higher among people aged 18 to 25 (8.9%) or 26 to 49 (8.5%) compared to Americans aged 50 and older (5.8%).