Experts Explore the Link Between Physical and Mental Health for Better Understanding

New research suggests that poor physical health may be a stronger indicator of mental health issues than brain scans. Scientists have long studied the connection between mental well-being and physical well-being, and the ability to use one to clarify the other helps healthcare professionals and patients alike. About 20% of American adults live with mental illness, and a recent National Institutes of Health survey found that nearly half of all Americans surveyed reported feeling depressed or anxious.

To expand the growing body of research on how mental and physical health are closely linked, researchers in Australia used data banks of adults in the U.S., U.K., and Australia. The study compared nearly 86,000 people with psychiatric disorders to about the same number of people who did not. The data revealed that poor physical health, particularly when it involved the metabolic, liver, or immune system, was a better indication of poor mental health than brain changes that show up on an MRI.

The study’s lead author noted that her team was surprised by the findings, as mental illnesses are typically understood as disorders of the brain. The research was not able to determine whether or not the connection was related to people having a more difficult time taking care of their physical health when they were also struggling with poor mental health, or if the connection is related to something else. Further research will need to examine why poor mental health appeared to be tied specifically to poor liver, immune system, and metabolic health. 

For now, mental health professionals and physicians need to work more closely together to monitor and attend to the physical health of these people, even from very early stages of psychiatric and mental care. The relationship between mental health and physical health is complex and bidirectional, meaning physical health and mental health affect each other. Past research has documented how mental illnesses such as anxiety can create a feedback loop with a wide range of physical symptoms, which may cause people with psychiatric conditions to not get diagnosed with physical illness in the same ways that healthcare providers diagnose people without the conditions.

“My glib answer to that is you can’t,” Dr. Denninger stressed. “These things are so closely intertwined that it’s very difficult to tell what’s being caused by the brain and what is being caused by the body. It’s a complex system...anytime we have something going on in our bodies, our brain plays a role.” 

The important thing to understand is that it’s vital for people treating patients with psychiatric conditions to also enable people to take care of their physical health and address associated concerns.

“We know that mental illness is associated with reduced life expectancy,” added Tian. “And the majority of deaths in people with mental illness relates to poor physical health.”

While it’s difficult to draw a line between mental and physical ailments, Dr. Denninger recommended keeping a log of symptoms, both physical and mental (or emotional), to better understand what may be triggering a physical symptom.

For example, does a person tend to get sick more often when they are experiencing poor mental health, or does it seem to be unrelated?

“The big mystery about the mind-body connection is not the fact that there is a connection, but understanding for all these disorders,” he stressed. “What is the path from what happens in our brains to what we perceive in our bodies?”