The number of people who are mentally ill has increased more than fivefold since 1975, with a majority of them living in rural areas, according to a new study published in the journal Social Psychiatry and Psychiatric Epidemiology.
The research, published online today in the American Journal of Public Health, examined the prevalence of major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia in the general U.S. population between 2007 and 2013.
It found that the percentage of people living with a mental illness increased from 20.3% to 30.9% between 2007-2013.
It also found that people living in the poorest regions of the country have the highest rates of mental health problems.
Researchers analyzed data from the U. S. Census Bureau’s National Health and Nutrition Examination Survey, which collects data about mental health from nearly 11 million people.
They found that mental health disorders accounted for about a quarter of all mental health diagnoses.
The most common mental health diagnosis was depression, and about one-third of people in the lowest income quartile had a diagnosis of major depression.
Researchers also found a clear relationship between the severity of mental illnesses and the likelihood of having a mental health problem.
People who had more severe mental illnesses were more likely to have problems with functioning in daily life, to have suicidal thoughts or actions, and to experience negative affective reactions to everyday situations.
The findings were consistent across all socioeconomic groups, with people in higher-income groups more likely than people in lower-income communities to have a mental disorder, and people in rural communities more likely in lower income communities to report having a serious mental illness.
But they also found evidence that people in urban areas are at greater risk for mental health conditions than people living within the same community.
They also found significant differences in rates of depression and bipolar disorder between the wealthiest and poorest communities.
“Our findings indicate that communities with a history of high rates of childhood poverty, such as those in the Deep South, are more vulnerable to mental health risks,” said lead author Robert J. Littman, a clinical psychologist at the University of Alabama at Birmingham.
“We found that among people living below the poverty line, the risk of experiencing a major depressive episode is higher in those who have been living with an underlying mental illness or a significant mental illness in childhood.
This is particularly true for people living among the poorest residents, who have higher rates of self-reported mental health difficulties and lower rates of reporting symptoms of mental distress.”
In addition to their role in the onset of a mental condition, people living at or near the poverty level are also more likely not to have access to the full range of mental-health care services available to low-income people.
For instance, mental health providers in the low- and middle-income regions have higher treatment rates, but they have lower rates for people who live in the poor communities.
“The gap between the treatment of the low income population and those of the high-income population is especially wide,” said Littam.
The researchers also found differences in the rates of schizophrenia and other psychiatric disorders among people in different socioeconomic groups.
People in the bottom quintile had higher rates than those in higher income groups for schizophrenia, while people in middle income had higher levels of both depression and other mental disorders.
They noted that these disparities in prevalence may be explained by differences in diagnosis, treatment, and care.
“For people who have a major depression diagnosis, the rate of depression is higher among people with schizophrenia,” said co-author Sarah B. Williams, PhD, a professor of psychiatry and behavioral sciences at the Emory University School of Medicine in Atlanta.
“There is no clear explanation for this difference.
For people with depression, the rates are similar.”
While it is not clear whether mental health services are more likely for people in high- and low-class communities, Littan and Williams believe the findings highlight the importance of taking steps to reduce disparities in mental health care, especially among people of color and people living on low incomes.
“I think that the most important message is that it’s not just about disparities, but about what we need to do to address mental health disparities and the barriers that they have to access these services,” said Williams.
“Because mental health is one of the top priorities of the administration, we need leaders to take steps to expand access to care and increase the access to mental-disease services, because they will have a huge impact on reducing the number of lives lost to mental illness.”
For more information about the findings, contact Littmans co-authors Katherine E. Bursch, PhD; and Jessica D. Jones, PhD.