Brain, lifestyle and environmental pathways linking physical and mental health

Depression and anxiety are prevalent in people with a chronic physical illness. Increasing evidence suggests that co-occurring physical and mental illness is associated with shared biological pathways. However, little is known about the brain’s role in mediating links between physical and mental health. Here, using multimodal brain imaging and organ-specific physiological markers from the UK Biobank, we establish prospective associations between the baseline health of seven organs including cardiovascular, pulmonary, musculoskeletal, immune, renal, hepatic and metabolic systems, and mental health outcomes at 4–14 years’ follow-up, focusing on depression and anxiety. We reveal multiple pathways, mediated by the brain, through which poor organ health may lead to poor mental health. We identify lifestyle and environmental factors, including exercise, sedentary behavior, diet, sleep quality, smoking, alcohol intake, education and socioeconomic status that influence mental health through their selective impact on the physiology of specific organ systems and brain structure. Our work reveals the interplay between brain, body and lifestyle, and their collective influence on mental health. Pathways elucidated here may inform behavioral interventions to mitigate or prevent the synergistic co-occurrence of physical and mental disorders. In a large-scale UK Biobank study of multimodal brain imaging and physiological markers, the authors find brain-mediated patterns of organ function and lifestyle pathways that are predictive of specific mental health outcomes.