Depression isn't just a serious mental condition — it can exacerbate chronic disease and should be tackled head-on, urges the World Health Organization in an article published Friday in the Lancet.

According to the study, after heart disease, depression is expected to become the second-leading cause of disease burden by the year 2020.

Depression had the largest effect on worsening health compared to the other chronic conditions, such as arthritis, the study found.
(CBC)

The depression rates of 245,404 adults, aged 18 and over, from around the world were studied in relation to four chronic diseases: angina, arthritis, asthma and diabetes.

Twenty-six countries from the European region participated, as did 15 from Africa, six from the Americas, four from the eastern Mediterranean region, five from southeast Asia, and four from the western Pacific region, for a total of 60 countries.

Researchers discovered the prevalence of one depressive episode alone among participants in the previous 12 months was 3.2 per cent. For angina, the prevalence was 4.5 per cent, for arthritis 4.1 per cent, for asthma 3.3 per cent and for diabetes 2 per cent.

An average of between nine and 23 per cent of the study's participants had one or more chronic physical diseases along with depression, which was significantly higher than the likelihood of having depression without suffering from a chronic physical disease, say the study's authors.

"After adjustment for socio-economic factors and health conditions, depression had the largest effect on worsening health compared with the other chronic conditions," reads the study.

"Consistently across countries and different demographic characteristics, people with depression plus one or more chronic diseases had the worst health scores of all the disease states."

The study's authors conclude that being depressed significantly worsens a person's health if they also suffer from another chronic illness.

Yet, the authors note, depression has traditionally not been factored into the overall health picture, and is not seen as being on par with other chronic health conditions in terms of its impact on a person's well-being.

And they feel this view jeopardizes successful treatment of the condition — a situation that needs to be changed.

"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," reads the report.

"Without treatment, depression has the tendency to assume a chronic course, be recurrent, and over time to be associated with increasing disability."