New data from the Centers for Disease and Control and Prevention reveal that nearly 1 in 10 U.S. adults met criteria for current depression. Women and nonwhites are at the greatest risk.
The CDC said in its Morbidity and Mortality Weekly Report, released Sept. 30, that by the year 2020, depression is expected to be second only to cardiovascular disease in disease burden. In 2004, depression was the third leading cause of disease burden worldwide and a leading cause of disability in high-income countries.
The CDC warned that depression can exacerbate chronic conditions such as arthritis, asthma, cardiovascular disease, cancer, diabetes, and obesity, all of which can contribute to increased work absenteeism, short-term disability, and decreased productivity.
Using Behavioral Risk Factor Surveillance System telephone survey data from 2006 and 2008 involving 235,067 adults aged 18 and older in 45 states, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands, the CDC found that 9% met criteria for current depression, including 3.4% who met criteria for major depression (MMWR Morb. Mortal. Wkly. Rep. 2010;59:1229-35).
The criteria for current depression were based on the Patient Health Questionnaire 8. People were considered to have major depression if for “more than half the days” they met at least five of the eight criteria, including at least one of the following: “little interest or pleasure in doing things” or “feeling down, depressed, or hopeless.”
The report showed a significant difference in the prevalence of depression between men and women. Four percent of women reported major depression, compared with 2.7% of men. “The greater prevalence of depression among women is not fully understood, although potential contributors include different responses to stressful life events, genetic predisposition, and hormonal differences,” the report said.
Non-Hispanic blacks, Hispanics, and non-Hispanics of other races were all more likely to report major depression (4%, 4%, and 4.3%, respectively) than were non-Hispanic whites (3.1%). The researchers explained that this disparity is consistent with greater risk factors of mental illness in these populations stemming from “social and economic inequality, exposure to racism and discrimination, increased prevalence of some chronic diseases, and less access to care and treatment for mental health and health conditions.”
According to the report, increase in age reflected an increase in the prevalence of depression. The prevalence of major depression ranged from 2.8% among those aged 18-24 years to 4.6% among those aged 45-64. There was a decline to 1.6% among those older than 65.
In addition to age, factors such as socioeconomic status, amount of education, employment status, and access to health insurance played a significant role in the prevalence of depression. For example, 22.2% of people unable to work and 9.8% of those unemployed were more likely to report major depression, compared with 3% of homemakers and students, and 2% of employed individuals.
By state, North Dakota reported the lowest prevalence of current and major depression (4.18% and 1.5%, respectively) and Mississippi reported the highest prevalence for current depression (14.8%) and major depression (5.3%).
The CDC suggests that states take an active role in health care interventions to help the increasing number of people in need of treatment for their depression. “States that monitor the prevalence of current depression and major depression can analyze their data by participant characteristics, identify those populations at greatest risk, and target them for interventions,” the report said.