Depressed WomanNew research from the World Health Organization (WHO) suggests that depression can be far more damaging than four common, chronic illnesses — arthritis, angina, asthma and diabetes.

Researchers from the World Health Organization examined data from over 245,000 people from 60 countries across the world.

They found that depression has the largest effect on worsening health compared with the other listed chronic illnesses, even after adjustments were made for socioeconomic factors and health conditions. Depression, accompanied by one or more chronic diseases gave patients the worst health scores. Surprisingly, the health scores did not vary much from country to country, even from poor to wealthy countries.

Depression also worsened health scores when it was diagnosed with any of the other four health conditions to a greater extent than when any other pair of these conditions were combined. For instance, depression and diabetes ranked a worse health score than diabetes and angina.

The combination of diabetes and depression was the most disabling of all.

The study also found on average that between 9 percent and 23 percent had depression in addition to one or more of four other chronic health conditions.

“We report the largest population-based worldwide study to our knowledge that explores the effect of depression in comparison with four other chronic diseases on health state,” the researchers said. The study appeared in the medical journal, Lancet.

Somnath Chatterji, who led the study, said, “These results indicate the urgency of addressing depression as a public health priority to reduce disease burden and disability, and to improve the overall health of populations.”

And he called on doctors treating physical illnesses to ensure they treat the mental health components of such conditions.

Commenting on why depression is so prevalent, Gavin Andrews and Nickolai Titov from the Clinical Research Unit at the Univeristy of New South Wales in Syndey point out it can affect people at any age and can reoccur at any time. Many people will cycle in and out of periods of depression throughout their lives. A shortage of treatment often compounds the problem, they note.

The researchers found that the prevalence of a depressive episode during the previous year was 3.2%. For health conditions, the prevalence was 2% for diabetes, 4.1% for arthritis, 5.4% for angina, and 3.3% for asthma.

Sources: The Lancet (v370) and wire reports