Study reveals how physical health affects mental health through brain pathways

Multiple biological pathways involving the organs and brain play a key role in physical and mental health, according to a novel study from UCL, the University of Melbourne and the University of Cambridge.

A study published in Nature’s Mental Healthanalysed UK Biobank data from over 18,000 people. Of these, 7,749 had no major clinically diagnosed medical or mental health conditions, while 10,334 reported a diagnosis of schizophrenia, bipolar disorder, depression or anxiety.

Using advanced statistical models, researchers found a significant link between poorer organ health and increased depression symptoms, and that the brain plays an essential role in linking physical health and depression.

The following organ systems were studied: lungs, muscles and bones, kidneys, liver, heart, and the metabolic and immune systems.

Dr Ye Ella Tian, ​​lead author of the study from the Department of Psychiatry at the University of Melbourne, said: “Overall, we found a number of essential pathways through which destitute organ health can lead to destitute brain health, which in turn can lead to destitute mental health.

“By integrating clinical data, brain imaging, and a wide range of organ-specific biomarkers in a immense population-based cohort, we have for the first time established multiple brain-mediated pathways through which destitute physical health of organ systems can lead to destitute mental health.

“We identified modifiable lifestyle factors that could potentially lead to improved mental health through their effects on specific organ systems and neurobiology.

“Our work provides a holistic characterization of brain, body, lifestyle and mental health.”

Physical health and lifestyle factors such as sleep quality, diet, exercise, smoking and alcohol consumption were also taken into account.

While it’s common knowledge in healthcare that all organs and body systems affect each other, this is rarely reflected in scientific studies. So it’s exhilarating to see these results because they really highlight the value of combining measurements from different parts of the body.”

Professor James Cole, study author, UCL Computer Science

Professor Andrew Zalesky, author of the study from the Departments of Psychiatry and Biomedical Engineering at the University of Melbourne, said: “This is significant work because we have shown the link between physical health and depression and anxiety, and how this is partly influenced by individual changes in brain structure.

“Our results suggest that destitute physical health in multiple organ systems, such as the liver and heart, the immune system, and the muscles and bones, can lead to later changes in brain structure.

“These structural brain changes may lead to or exacerbate symptoms of depression and anxiety, as well as neuroticism.”