Researchers have published a landmark study in Nature Mental Health that has now revealed the biologically intricate pathways linking poor physical health to mental health issues, mediated through the brain. The collaborative study, led by the University of Melbourne in tandem with University College London and the University of Cambridge, has for the first time revealed how the body’s different organ systems are interconnected for mental well-being.
In a study of over 18,000 UK Biobank cohort participants, poor health across multiple organ systems was associated with higher levels of sickness depression, and anxiety. The health of seven key organ systems was considered: lungs, muscles and bones, kidneys, liver, heart, metabolic, and immune systems. They further identified a very strong association of poor organ health, especially among the musculoskeletal, immune, metabolic, and hepatic systems, with the progression of symptoms of mental ill health.
Dr. Ye Ella Tian, the Research Fellow in the Department of Psychiatry at the University of Melbourne and lead author of the study said, “The findings are novel because this is the first time an association like this has been made.”. “The innovative aspect was that we integrated clinical data, brain imaging, and a large set of organ-specific biomarkers obtained for the first time in a population-based study to explore the first mechanisms in which the brain acts as a mediating factor through which poor physical health of body organ systems may lead to poor mental health.”
It is associated with some lifestyle factors due to smoking, alcohol use, physical inactivity, poor nutrition, and inadequate sleep; it significantly influences not only physical but also mental health. The only thing is that such factors strongly relate to depressive and anxiety symptoms in the general and holistic approach toward health.
The authors, with the use of advanced statistical models and braining imaging data, observed that the greatest predictor of depression symptom burden was the volume of gray matter in the brain and that brain structure mediates the relationship between physical and mental health with the solid effect noted to be more prominent in the musculoskeletal and immune systems.
“Our results suggest that several states of ill health, mental and physical—liver, heart, immune system, musculoskeletal, and metabolic system—may lead, in turn, to changes in brain structure. We can speculate that the brain structural changes lead to, and amplify depression, anxiety, and neuroticism symptoms.
The authors of this study did not overlook various limitations, including a percentile white British cohort and a series of participant assessments that did not make allowance for careful assessment of the pathways by which poor mental health might lead to poor physical health. They called for further inquiry to test for the generalization of these results across ethnicities and different social contexts.
This was confirmed by Dr Modon Deyg MGB of the University of Sydney, School of Medicine and Health, Research Fellow that the results were well summarized and with the inclusion of life and health factors, brain imaging, and organ-specific biomarkers incorporated by the researchers; ability now to pinpoint the key pathways in which physical health impacts mental health through biological mechanisms is possible.
This groundbreaking study characterizes a new holistic view of the brain-body-lifestyle-mental health interconnectedness and opens novel avenues for improving mental health through targeted interventions in physical health and lifestyle modifications.