Depression Worsens Health More Than Angina, Arthritis, Asthma, or Diabetes

Marlene Busko

September 11, 2007 — Worldwide, depression worsens health more than 4 common chronic diseases — angina, arthritis, asthma, and diabetes — and, in what is described as a "silent scandal," most people who are mentally ill are not treated.
These findings are from 2 large international studies published in the September 8 issue of the Lancet, which also features 2 other articles that begin a 6-part series on global mental health.
Depression More Damaging Than Physical Chronic Illness
In the first study, Saba Moussavi, from the World Health Organization (WHO), in Geneva, Switzerland, and colleagues explain that worldwide, the lifetime prevalence of depression is 2% to 15% and it accounts for almost 12% of total years lived with disability. They add that, to their knowledge, there has been no worldwide comparison of depression with other chronic diseases and their effect on health. They aimed to investigate this using data from the WHO World Health Survey.
They analyzed available data from 245,404 adults aged 18 years and older from 60 countries representing all regions of the world who had completed the survey, mainly in face-to-face interviews. Depression was defined according to International Classification of Diseases-10th revision (ICD-10) diagnostic criteria.
The researchers found that 3.2% of the study participants reported having a depressive episode in the past 12 months, and the prevalence of angina, arthritis, asthma, or diabetes alone did not exceed 5%.
An average of 9.3% to 23% of the survey respondents with 1 or more of the 4 chronic physical illnesses also had depression.
After adjustment for socioeconomic factors, the mean health score was significantly lower in respondents with depression (72.9 on a scale of 0 to 100) compared with respondents with other chronic conditions (78.9 – 80.3; P < .0001).
Having more than 2 chronic physical diseases without depression was consistently linked with a smaller negative impact on heath compared with having depression alone or having depression and 1 other chronic physical disease.
"Depression produces the greatest decrement in health compared with the chronic diseases angina, arthritis, asthma, and diabetes," Dr. Moussavi and colleagues write. They add that it is urgent to make depression treatment a public health priority to reduce disease burden. "Primary care providers must be taught not to ignore the presence of depression when patients present with a physical condition, in view of the marked effect it has on an individual's health."
Comment: Need to Improve Rate of Acceptable Depression Treatment
In an accompanying comment, Gavin Andrews, PhD, and Nickolai Titov, MD, from the University of New South Wales, in Sydney, Australia, concur with Dr. Moussavi and colleagues that depression is very disabling. They speculate that if a laboratory test could confirm the diagnosis of depression, doctors might be more assertive about insisting that patients adhere to treatment.
They draw attention to the need to improve the rate of acceptable depression treatment: "In Australia, less than 30% of patients receive good treatment with antidepressants, cognitive behavioral therapy, and proactive maintenance care. By contrast, 80% of patients with arthritis and 90% of patients with asthma receive an acceptable standard of care. . . . Treatment for depression should at least be on par with that for other chronic illnesses."
Unmet Mental Health Needs Are Pervasive
In a second study, Philip S. Wang, MD, from the National Institute of Mental Health, in Rockville, Maryland, and colleagues report that mental health needs for anxiety, mood, and substance disorders in 17 countries are largely unmet, and the treatment deficit is "especially concerning" in less developed countries.
The group analyzed data from 84,850 adults living in low- to middle-income countries (Colombia, Lebanon, Mexico, Nigeria, China, South Africa, and Ukraine) and high-income countries (Belgium, France, Germany, Israel, Italy, Japan, Netherlands, New Zealand, Spain, and the United States) who replied to a WHO World Mental Health Survey that assessed the use of mental health services in the previous year.
The use of mental health services was lower in low-income countries; for example, 2% of respondents in Nigeria vs 18% of respondents in the United States had used mental health services in the previous year. The percentage of respondents who received care for severe mental health disorders ranged from 11% (in China) to 61% (in Belgium). The proportion of respondents who received at least minimally adequate treatment ranged from only 10% (in Nigeria) to 42% (in France). In a few countries, less use of mental health services was reported by individuals who were male, married, less educated, or at the extremes of age or income.
"We need to understand how the few mental health resources that nations do have can best be allocated," the group writes. They note that the general health sector is the largest source of mental health services for most countries, and the way mental health services are used in developed nations might not translate to other nations.
Comment: "Specific Actions Needed to Redress this Silent Scandal"
In an accompanying comment, Prof. Graham Thornicroft, from King's College London, in the United Kingdom, writes that "Wang and colleagues have completed the largest international psychiatric epidemiological study so far," and "the disturbing clarity of its findings" overcomes potential study limitations.
He writes that "the first stark finding is that although up to 30% of the population is expected to have clear-cut mental illness every year, in every country studied, at least two-thirds of people who are mentally ill receive no treatment." He adds that in the United States, 31% of the population is affected by mental illness every year, but 67% are not treated; in Europe, the comparable percentages are 27% and 74%, respectively, whereas only 8% of diabetics receive no care.
The article also highlights the waste of resources, Prof. Thornicroft writes. "Almost unbelievably, of those treated, there were more with no disorders than with severe disorders for almost every country studied. In the [United States], every year a staggering 10% of the population is treated despite not being mentally ill. Wang does not give a financial value of this level of waste; I look forward to these data in a subsequent study." He concludes with a call to action: "What do these new data mean? They are a sobering global account of how most people who are mentally ill are not treated and how many countries have no effective treatment triage. . . . Why have we allowed this global and gross neglect to persist and be denied for so long? Specific actions are needed now to redress this silent scandal."
The authors of the articles and comments declare they have no conflict of interest. The funding for the international mental health surveys is listed in the article by Dr. Wang and colleagues.
Lancet. 2007;370:851-858, 808-809, 841-850, 807-808.