Nearly 1 in 10 Americans suffers from clinical depression and 3% have major depression, according to a 2006-2008 survey of 235,000 adults from 45 states, the U.S. Virgin Islands, Puerto Rico and Washington, D.C. The survey, conducted by the Centers for Disease Control and Prevention (CDC), marked an uptick in rates of the mood disorder: a similar study conducted in 2001-2002 reported 6.6% of the population as depressed.
Survey participants were asked to answer questions about behaviors and lifestyle characteristics that are known to be associated with depression. These included questions about self-esteem, appetite loss or gain, sleeping too little or too much, and ability to concentration.
Researchers looked for commonalities among the people who reported symptoms of depression and identified a few factors that may have a relationship to the mood disorder. Primary among them was unemployment, which remains steady at 9.7%; about 6% of those with jobs reported symptoms of depression, compared with 21% of unemployed people surveyed. It is unclear from these statistics if depression causes job loss or job loss causes depression, though some evidence suggests the latter.
Rates also varied across the country. For example, Mississippi had the highest rate of depression, at 15% of responses, while North Dakota was lowest, at 5%. Overall, the Southeast seemed to be the most melancholy, according to CDC epidemiologist Leila McKnight-Eily, who told HealthDay:
The clustering of depression in the Southeast may be partly due to chronic health conditions, such as obesity, heart disease, stroke and sleep problems, which are also common in the area, she said.
“In addition, there could also be differences in socioeconomic status, the presence of other mental health conditions and also access to health care and treatment,” McKnight-Eily said.
For more on the study and what you can do if you suspect that you or someone you know is depressed, see the CDC study in its entirety. For the American Psychiatric Association’s new guidelines on depression treatment, see my colleague John Cloud’s story published Friday.