MARCH / APRIL 2004

FORUM

Mental illness and the global burden of disease

Despite its ravages, mental illness continually struggles with a sort of second-tier status in popular opinion, both in the U.S. and around the world. And yet it is one of the most prevalent and devastating afflictions known to mankind. More than 450 million people around the world suffer from some form of mental or behavioral disorder, dwarfing the figures associated with HIV/AIDS and diabetes. Mental illness goes alarmingly undermined, under-treated, and misunderstood—all to damaging effect. Difficulties in diagnosis, as well as cultural stigmas that prevent many from confronting mental health issues, contribute to the widening gap between the problem and the resources devoted to it. Researchers who study the Global Burden of Disease (GBD), an indicator of disease-related hardships, estimate that mental illness accounts for 11.5 percent of the total global burden—that’s more than the burden caused by all forms of cancer. And the numbers are growing.

Leading the field in GBD research are the World Bank, World Health Organization (WHO), and the Harvard School of Public Health. Together, they published The Global Burden of Disease, a report claiming that unipolar major depression, alcohol abuse, bipolar disorder, schizophrenia, and obsessive-compulsive disorder represented half of the leading causes of disability worldwide in 1990.

The Global Burden of Disease study projects that by 2020, psychiatric and neurological conditions could increase their share of the total global burden by nearly half, to almost 15 percent. HMI World spoke with two mental health professionals in the Harvard community to learn more about the global burden of mental illness: Dr. Miles Shore, Harvard Medical School’s Bullard Professor of Psychiatry, and Dr. Myron Belfer, a psychiatrist at Harvard’s Department of Social Medicine, as well as a senior advisor to the WHO for its recent publication, Caring for Children and Adolescents with Mental Disorders.

Dr. Myron Belfer

The changing face of illness
While the burden of mental illness may be growing, that doesn’t necessarily mean that more people are becoming mentally ill. Belfer said that it is unclear whether cases of mental illness are increasing, but that “we are getting better at diagnosing mental illness and disseminating information.” What’s more, an epidemiological shift is occurring globally. Better treatments for many primarily physical diseases have tipped the balance, making mental illness account for a larger proportion of all disease. This, according to Dr. Shore, is a “good news, bad news” situation. “Except for some southern-tier countries, internationally, people are getting healthier,” he said. “It’s good because people don’t die as much; it’s bad because now the burden shifts from mortality to morbidity.”

Although people with serious mental illness do not suffer a substantial increase in mortality, they nevertheless suffer from what is considered a loss of “functional life.” The disabilities associated with mental illness are often quantified in “disability adjusted life years” (DALYs), which reflect the total amount of healthy, functional years lost to a disease. Using DALYs as an indicator, the National Institutes of Mental Health estimate that major depression ranks second only to ischemic heart disease in measuring GBD in established market economies. Already, major depression is the leading cause of disability worldwide among persons age five and older. More than 150 million people worldwide are thought to be depressed today.

Leading Causes of Disability in the World, 1990

The high cost of mental illness
This loss of functional life years imposes massive direct and indirect economic burdens, not only on those who suffer from mental illness, but on the families, communities, industries, and entire nations affected. For those living with a mental illness, lost wages, treatment costs (including therapy, hospitalization, and pharmaceuticals), denial of employment and educational opportunities, and poor job retention are key contributors to the personal burden. Employers suffer from reduced productivity and increased absenteeism. By some estimates, mental illness accounts for up to 10 percent of all insurance claims, and 45 percent of workplace absenteeism.

The WHO reported in Investing in Mental Health (2003) that the cost of mental illness in developed countries is three to four percent of the gross national product. The United States alone spent $148 billion in 1990. Furthermore, mental illness is also linked to physical illness—and its attendant costs. Just as the effects of physical illness can lead to negative changes in mood and concentration, so too can mental illness contribute to heart disease, suicide, and physically unhealthy behaviors, such as over- or under-eating, substance abuse, and risky sexual activity. Studies have also shown that depression brought on by a physical disease (so-called “co-morbid depression”) can exacerbate the gravity of the physical illness, which can in turn intensify the mental symptoms.

Dr. Miles Shore

Seeking treatment, treating seekers
Treating mental illness is not cheap, but it’s still much cheaper than leaving it untreated. Even so, most middle- and low-income countries devote less than one percent of their health care expenditures to mental health, and it is often in these countries where access to quality care is needed most. Mental illness does not discriminate amongst cultures. But there is no doubt that many of its forms are more prevalent in poorer populations, whose conditions (including increased violence, malnutrition, unemployment, and inadequate education) can be contributors. “War, auto accidents, and violence in general all contribute to what we can call an epidemic of depression,” said Shore.

Despite efforts to increase awareness about mental illness and mental health topics in general, the subject remains mired in stigma and prejudice. In many cases, that stigma extends beyond those directly affected and onto their families and communities as well. According to the WHO, as many as two-thirds of all people with a diagnosable mental disorder do not seek treatment, whether for fear of being stigmatized, or for fear that the treatment may be worse than the illness itself. The WHO also reports that worldwide, 65 percent of psychiatric beds are in mental hospitals, rather than general hospitals and community rehabilitation locations.

And though the West has made inroads in diagnosing and treating mental disorders, the developing world remains hindered by a lack of available drugs, inadequate training for health care providers, and poorly orchestrated treatment programs. “The drugs don’t do any good if they don’t reach people,” said Shore. The WHO reports that up to 20 percent of countries lack at least one common antidepressant or antipsychotic in primary care.

Looking ahead
Prevention and promotion programs are foremost among recommended strategies to improve the world’s mental health outlook. Already, businesses in the U.S., U.K., and Canada are beginning to see the economic benefit of helping mentally ill workers, particularly those with depression. “There is a strong business case to be made for helping depressed workers,” Shore said.

The WHO approved a 2002 resolution entitled “Strengthening Mental Health,” in which it called for governments, corporations, and the general public to, among other things, “enhance the visibility of mental health, and to raise public and professional awareness of the real burden of mental disorders.” Since 1991, the WHO has advocated its Mental Health Global Action Plan, centered on four principles: improving information dissemination, raising awareness and advocacy, sharing resources between countries, and enabling local service options in poorer areas.

In February, Dr. Benedetto Saraceno, director of the WHO Department of Mental Health and Substance Dependence, gave a series of lectures on international mental health initiatives at the HMS Department of Social Medicine. He stressed that for the World Health Organization, the time for discussing the burden of mental illness has passed—leaders in mental health at both the local and global level must now focus on implementing plans that address the burden. “We have to show the world that we are changing something,” he said.

The WHO has worked to transform the generic tenets behind the Mental Health Global Action Plan into hundreds of more specific, measurable indicators to help gauge mental health problems in a given community. These indicators help form the basis of a GRANT, or Gap Reduction Achievable National Target, which is a plan to address specific mental health issues that have been identified in a country. The idea is to give a country milestones of improvement that are not only relevant to its problems, but that are designed to enable success. “Geneva (where the WHO is headquartered) tends to think that everything is possible, while countries tend to think nothing is,” said Saraceno.

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