The damage that co-morbid depression has on a patient’s health is greater than that caused by such chronic illnesses as diabetes, angina, asthma and arthritis, according to an article published in The Lancet. In other words, depression with diabetes is more damaging than diabetes with angina or asthma or arthritis.

Dr Somnath Chatterji, World Health Organisation (WHO), Geneva, Switzerland and team looked at data on 245,404 people from the World Health Survey (WHO). They discovered that the prevalence of a depressive episode during the previous year was 3.2% – for diabetes this figure was 2%, for arthritis 4.1%, for angina 5.4% and for asthma 3.3%.

They found that a large number of people had one or more of these chronic diseases as well as depression – between 9% to 23% of them.

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 disease(s) gave patients the worst health scores – these scores did not alter much from country to country around the globe.

“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,” the authors wrote.

An accompanying Comment pointed out that while 80% of patients with arthritis and 90% of patients with asthma receive an acceptable standard of care, the case is nowhere near the same for depression. “In Australia, less than 30% of patients receive good treatment with anti-depressants, cognitive behavioural therapy, and proactive maintenance 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.” The Comment was written by 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.

Written by: Christian Nordqvist