Study: The Mentally Ill Are More Likely to Be Physically Ill Too

People with mental health disorders are more likely to be diagnosed with chronic physical health conditions, according to a new study published Wednesday in JAMA Psychiatry.

The study reviewed data from the World Mental Health Surveys, an initiative distributed to 17 countries with diverse socioeconomic profiles, including poorer nations (Iraq and Colombia) and wealthier ones (Belgium, Italy, Poland, Japan, New Zealand, Spain and the U.S.).

The study looked at 16 mental health conditions and 10 chronic physical illnesses. These included mood and anxiety disorders, impulse control and substance abuse, along with arthritis, chronic pain, heart disease, stroke, hypertension, diabetes, asthma, chronic lung disease, peptic ulcers and cancer. Researchers conducted the surveys in person between 2001 and 2011 and asked 47,609 individuals about both their physical and mental health histories.

The researchers found that 3 to 13 percent of patients with physical conditions also had a history of a mood disorder. This included nearly 12 percent for anxiety disorders, almost 5 percent for impulse control disorders and more than 10 percent for substance use disorders. The study doesn't suggest that mental health conditions cause subsequent physical illnesses but instead identified that there may be some trending connection between the two.

Previous studies show that, overall, patients with mental illness tend to have poorer health outcomes than those who do not have a history of conditions such as mood disorders, anxiety and substance abuse. According to another study, people with psychiatric conditions—including schizophrenia, bipolar disorder and depression—have an overall mortality rate two to three times higher than the general population.

The researchers say their study does have some limitations. Study participants self-reported their physical and mental health histories, which probably left room for some inaccuracies, since patients may not recall the exact point when a condition began or the specifics of a doctor's diagnosis. Individuals also varied widely by age, and people who are older are more likely to have a history of several chronic health conditions and experience periods that are marked by anxiety or mood changes.

Additionally, other similar research finds people tend to underreport any history of mental illness. The study also doesn't take into account lifestyle factors that may affect the relationship between physical and mental health, such as genetics, diet and low birth weight.

Much of the data suggests lifestyle choices may be influencing this trend. For example, the researchers observed that people who reported a history of substance use disorders also had a much higher incidence of chronic lung disease. People who drink alcohol are much more likely to smoke, a main factor that contributes to lung conditions. Some of the data also reflects findings of other well-defined research, such as the link between high levels of anxiety and heart disease.

The study authors say the findings also point to this trend. They suggest health care providers treating patients with mental health conditions offer guidance for staying on top of preventive care and making better lifestyle decisions that could have a lasting impact on physical health.

"Current efforts to improve the physical health of individuals with mental disorders may be too narrowly focused on the small group with the most severe mental disorders," the researchers write. "Interventions aimed at the primary prevention of chronic physical diseases should optimally be integrated into treatment of all mental disorders in primary and secondary care from early in the disorder course."