Depression worsens health more than angina, arthritis, asthma, diabetes

Depression produces the greatest decrement in health compared with the chronic diseases angina, arthritis, asthma, and diabetes, conclude authors of an Article in this week's edition of The Lancet.

Dr Somnath Chatterji, World Health Organisation (WHO), Geneva, Switzerland and colleagues studied data from 245404 people included in WHO's World Health Survey. They found that the prevalence of a depressive episode in the previous 12 months was 3.2%; for angina this figure was 4.5%; for arthritis 4.1%; for asthma 3.3%; and for diabetes 2.0%. An average of between 9% and 23% of people had one or more of these chronic diseases and also depression, which was significantly higher than the likelihood of having depression in the absence of a chronic physical disease. After adjustment for socioeconomic factors and health conditions, depression had the largest effect on worsening health compared with the other chronic conditions. 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 authors conclude: "The co-morbid state of depression incrementally worsens health compared with depression alone, with any of the chronic diseases alone, and with any combination of chronic diseases without depression. 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."

In an accompanying Comment, Professor Gavin Andrews and Dr Nickolai Titov, Clinical Research Unit for Anxiety and Depression, University of New South Wales at St Vincent's Hospital, Sydney, Australia, say: "In Australia, less than 30% of patients receive good treatment with anti-depressants, cognitive behavioural therapy, and proactive maintenance care. By contrast, 80% of patients with arthritis and 90% of patients with asthma receive an acceptable standard of care. Perhaps differential access to treatment is one reason why disability is less with the physical disorders. Treatment for depression should at least be on a par with that for other chronic diseases."