People in wealthy nations have higher rates of depression than those living in lower-income countries, according to new study sponsored by the U.N. World Health Organization.
The researchers interviewed more than 89,000 people in 18 countries, and found that 15 percent of those living in high-income countries reported having an episode of depression, compared with 11 percent of those living in low-income nations.
France and the United States had the highest reported depression rates anywhere in the world, with 21 percent of French respondents and 19.2 percent of U.S. respondents reporting extended periods of depression within their lifetimes.
The researchers also assessed the frequency of Major Depressive Episodes (MDEs), in which a person suffers five out of the following nine criteria: sadness, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, low energy and poor concentration. They found that MDEs were elevated in high-income countries (28 percent compared with 20 percent), and were particularly high (over 30 percent) in France, the Netherlands, and the United States. The country with the lowest incidence was China, at 12 percent. However, MDEs were particularly high in India, at nearly 36 percent.
Some aspects of depression were cross-cultural, the study found. For instance, women were twice as likely to suffer depression as men, and the loss of a partner, whether from death, divorce or separation, was a major contributing factor.
The contribution of age varied from country to country, with age of onset almost two years earlier in low-income countries.
“This is the first study which uses a standardized method to compare depression and MDE across countries and cultures,” said Professor Evelyn Bromet from State University of New York at Stony Brook, one of the study’s leaders.
“We have shown that depression is a significant public-health concern across all regions of the world and is strongly linked to social conditions.”
“Understanding the patterns and causes of depression can help global initiatives in reducing the impact of depression on individual lives and in reducing the burden to society.”
The study was published July 25 in the journal BMC Medicine.
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