Depression Biggest Contributor to Global Disease Burden

Psychiatric illness and substance abuse are leading contributors to early death across t he globe, according to a recent World Health Organization (WHO) report.

The findings, from the global burden of disease report by the WHO that was released in October 2008, aimed to provide a comprehensive picture of the global and regional state of health. It was based on extensive government data on the causes of death and impact of disease and injuries. It provides projections of deaths and burden of disease to the year 2030.

“This study enables policymakers and countries to identify the gaps and ensure that help and efforts are directed to those who are most in need,” said the report's lead author, Colin Mathers, coordinator for Epidemiology and Burden of Disease at WHO, in a written statement.

The study, which is an update of the WHO research first conducted in 1990, found that neuropsychiatric conditions are among the leading causes of disability in all regions of the world and that they account for about one-third of “years lost due to disability” (YLD) among people older than 14. The authors defined YLD as the number of illnesses that occurred in a given year, multiplied by the average duration of the disease and further multiplied by the severity.

The neuropsychiatric conditions—ranked from most to least prevalent—were depression, alcohol dependence/problem use, bipolar disorder, schizophrenia, Alzheimer's/dementias, panic disorder, and drug dependence/problem use.

The extent of mental illness worldwide and its impact on people in both high-income and low-income countries was not surprising to Steven Sharfstein, M.D., president and chief executive officer of the Sheppard Pratt Health System in Baltimore and a past APA president.

“Diseases of the brain which impair the ability of an individual human to cope with and adapt to the vicissitudes of life are the leading public health challenge today,” said Sharfstein, who has studied the impact of mental illness around the world.

Depression Taking Highest Toll

Depression was identified in the WHO report as the leading global cause of years of health lost to disease in both men and women. Unipolar depression made a large contribution to the worldwide burden of disease, according to the study, including its role as the eighth leading cause of loss of health in low-income countries and the primary cause of loss of health in middle- and high-income countries.

“Depression is a huge international problem,” said Lawrence Hartmann, M.D., chair of APA's Council on Global Psychiatry and a past APA president, adding that the recent WHO report echoed similar findings of previous research on the worldwide extent of mental illness.

Compared with men, the worldwide rate of depression in women was 50 percent higher, and women and girls had higher rates of anxiety disorders, migraine, and Alzheimer's and other dementias.

The findings on the particular impact of mental illness on women were expected by Pedro Ruiz, M.D., a member of the Council on Global Psychiatry, a past president of APA, and now president-elect of the World Psychiatric Association. He said this part of the report reflects the particular burdens many women face in raising children alone.

“Now that we know this, we have to accept the challenge and take action,” Ruiz said about the worldwide need for more psychiatric research and prevention initiatives.

The report also highlighted the extensive toll that substance abuse and addiction have taken on the world's population. The authors found that among countries of all income levels, alcohol dependence and problem use are among the 10 leading causes of disability.

“The male burden for alcohol and drug use disorders is nearly seven times higher than that for female and accounts for almost one-third of the male neuropsychiatric burden,” wrote Mathers and his colleagues.

The authors noted that their calculations of life years lost to alcohol abuse include only the direct burden of alcohol dependence and problem use, while the total “attributable burden of disability” stemming from alcohol use is much larger.

Translating Data Into Intervention

The authors said that they envisioned that countries would use the information to create strategies and cost-effective interventions aimed at improving the health of their populations. However, psychiatrists are skeptical that it will have much impact on mental health care, including substance use treatment, in many areas of the world.

“There is an increase in interest in the epidemiology of mental illness, and that is very welcome,” Hartmann said. “Until the last decade, people haven't been very good at studying the epidemiology of what exists. We're now somewhat better at that, and it is very useful.”

Hartmann said that the full extent of mental illness and addiction needs much more attention from country leaders to get the resources needed for treatment, and reports such as the recent WHO findings should help in that effort.

Ruiz was less optimistic about the impact of more information on the amount of mental health care and substance use treatment funded worldwide. While parity coverage of mental illness was recently approved on the federal level in the United States, many countries spend less than 1 percent of their gross domestic product on such care. One measure of the low priority given to mental health care is the low number of psychiatric hospital beds funded, even in many middle-income countries.

“We are recognizing mental illnesses more—no question” Ruiz said. “The problem is that although we recognize them, we are often not providing the proper treatments for them.”

Global Burden of Disease 2004 Report” is posted at<www.who.int/healthinfo/global_burden_disease/2004_report_update/en/index.html>.▪