By Amy Norton
WEDNESDAY, Feb. 11, 2015 (HealthDay News) -- People with mental health conditions such as depression, chronic anxiety and schizophrenia tend to die at younger ages than their peers without psychiatric disorders, a new research review says.
In fact, the researchers estimated that mental health disorders typically rob people of nearly a decade of life, and account for 8 million deaths worldwide each year.
The findings, published online Feb. 11 in JAMA Psychiatry, come from an analysis of over 200 international studies spanning several decades. Researchers said the studies help put the global toll of mental health disorders into perspective.
Although the study found an association between mental health conditions and earlier death, it wasn't designed to prove that the disorders were a direct cause of the early deaths.
When people think of lives lost to mental illness, they might automatically focus on one cause of death -- namely, suicide, said Dr. Mark Olfson, a professor of clinical psychiatry at Columbia University Medical Center in New York City.
"But studies like this broaden our perspective," said Olfson, who was not involved in the research. "The risk includes deaths from natural causes, and we see higher mortality across a range of mental health disorders."
Schizophrenia and other types of psychoses -- among the most severe forms of mental illness -- carried the highest mortality rates across the studies. But, Olfson noted, conditions such as major depression and anxiety disorders are far more common, and they also appeared to shorten people's lives.
Overall, the analysis found, people with mental health conditions were more than twice as likely to die over roughly 10 years, versus people without the disorders.
Their risk of death from "unnatural causes" -- including suicide and accidents -- was seven times higher. But their odds of dying from physical health conditions were also elevated, by an average of 80 percent, according to the study.
"People with mental health disorders have a high prevalence of chronic medical conditions," said study leader Elizabeth Walker, a researcher at the Emory University Rollins School of Public Health in Atlanta.
Making matters worse, she said, they often have difficulty managing those conditions -- whether because of poor diet, lack of exercise, trouble sticking with medications, or problems getting the health care they need.
Olfson agreed, noting that physical health issues like obesity and type 2 diabetes -- common among Americans, in general -- are particularly common among people with psychiatric disorders. And both raise the risk of heart disease and other ills.
"We've known for some time that depression, for example, interferes with people's adherence to treatment for chronic health conditions like diabetes," Olfson said.
Yet the situation does not seem to be improving: Walker's team found that the mortality "gap" between people with and without mental disorders has grown over time -- becoming wider in studies done since the 1990s, versus those done prior to 1970.
Part of that could be due to healthier lifestyle habits in the general population, according to Olfson. Smoking, for example, has declined overall, but is still prevalent among people with mental health conditions, he noted.
Whatever the specific reasons, Walker said it appears that people with psychiatric conditions are not seeing the same physical health improvements as the overall population.
"There's no simple solution to this," she said. "It's going to take multiple approaches."
One approach is to make sure that people with psychiatric disorders have access to all the types of health care they need, according to Walker. She noted that Americans with mental health issues also have higher-than-average rates of poverty and unemployment, and may also lack the "social support" -- family and friends -- that can help them deal with chronic ills.
Both Walker and Olfson also pointed to the need for more "integrated care" -- which essentially means better coordination among the different professionals responsible for a patient's mental and physical health.
As for families of people with mental disorders, Olfson said they should be aware of the potential physical toll -- and do what they can to support a healthy lifestyle.