1 in 10 Americans Depressed

In time for National Depression Screening Day (October 7, 2010) and Mental Illness Awareness Week (October 3-9, 2010), the Centers for Disease Control and Prevention (CDC) published survey data on depressed mood in the United States.

The report summarizes responses to a standardized questionnaire administered in 2006 and 2008. The researchers asked 235,067 adults about symptoms during the 2 weeks prior to receiving the call.

On average, 9% percent of respondents met the criteria for some type of depression. About one-third of those with depression had Major Depression, a relatively severe form. Regional variations were broad — the rate of depression in Mississippi was almost 15%, while the rate in North Dakota came in under 5%. The authors suggested that these differences might be explained by socioeconomic factors or variations in access to mental health care.

Broad population surveys are interesting and useful — the CDC report reflects an enormous amount of work. Still, the results are inevitably difficult to interpret. It’s worth following the link to read the details. Be sure to scroll down to the editorial note, where the authors describe some limitations of the survey. For example, telephone surveys don’t necessarily reach people who use mobile phones rather than landlines. And the survey also doesn’t capture people who are either homeless or living in institutions.

The survey, which appears online on the CDC website, is available to the public. You won’t need a degree in statistics to follow it, but it will give you a taste for the complexity of depression research.

• Centers for Disease Control and Prevention (2010). Current Depression Among Adults — United States, 2006 and 2008 Morbidity and Mortality Weekly Report 59:1229-1235.
• National Depression Screening Day is October 7, 2010. For more information and self-assessment tools: http://www.mentalhealthscreening.org/
• Mental Illness Awareness Week is October 3-9, 2010. For more information: http://www.nami.org/