Photo of a depressed woman holding her face
Depression rates are elevated in high income-countries

Depression – more than a feeling

26 July, 2011

Depression can affect a person’s ability to work, form relationships, and destroy their quality of life. At its most severe depression can lead to suicide and is responsible for 850,000 deaths every year. It is a worldwide problem, say scientists; one that can be linked to our social environment and living conditions.

In conjunction with the World Health Organization World Mental Health (WMH) Survey Initiative, researchers from 20 international centres collaborated to investigate how common depression is around the globe. The scientists also compared social conditions with depression in 18 countries.

Based on detailed interviews with over 89,000 people, the results showed that 15% of the population from high-income countries (compared to 11% for low/middle-income countries) were likely to get depression over their lifetime with 5.5% having had depression in the last year.

Incidence of major depressive episodes was also tracked. To be classified as having had a major depressive episode a person was additionally required to fulfil 5 out of 9 criteria including sadness, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, low energy and poor concentration.

Major depressive episodes were elevated in high-income countries (28% compared to 20%) and were especially high (over 30%) in France, the Netherlands, and America. The country with the lowest incidence was China at 12% but, in contrast, major depressive episodes were very common in India (at almost 36%).

Some aspects were cross cultural – women were twice as likely to suffer depression as men and the loss of a partner, whether from death, divorce or separation, was a main contributing factor. But, the contribution of age varied from country to country.

The age when depression first appeared was almost two years earlier in low income countries and, while the amount of difficulty a person had with aspects of their life increased with depression and how recent their last attack was, it was more apparent in people from high income countries.

The authors conclude 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,” they said.