Affiliation: | 1. Institute for Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Deakin University, Geelong, VIC, Australia;2. Psychosis Research Unit, Aarhus University Hospital - Psychiatry, Aarhus, Denmark Department of Clinical Medicine, Aarhus University, Aarhus, Denmark;3. Department of Psychiatry and Amsterdam Public Health, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands;4. Division of Psychology and Mental Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK Greater Manchester Mental Health NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK;5. Centre for Mental Health, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia;6. National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark Queensland Centre for Mental Health Research, Park Centre for Mental Health, Brisbane, QLD, Australia Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia;7. Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital, Aarhus, Denmark;8. National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital, Aarhus, Denmark;9. Queensland Centre for Mental Health Research, Park Centre for Mental Health, Brisbane, QLD, Australia Metro South Addiction and Mental Health Service, Brisbane, QLD, Australia Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia;10. Centre for Youth Mental Health, University of Melbourne, Parkville, VIC, Australia Orygen, Parkville, VIC, Australia;11. Institute for Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Deakin University, Geelong, VIC, Australia Centre for Youth Mental Health, University of Melbourne, Parkville, VIC, Australia |
Abstract: | Populations with common physical diseases – such as cardiovascular diseases, cancer and neurodegenerative disorders – experience substantially higher rates of major depressive disorder (MDD) than the general population. On the other hand, people living with MDD have a greater risk for many physical diseases. This high level of comorbidity is associated with worse outcomes, reduced adherence to treatment, increased mortality, and greater health care utilization and costs. Comorbidity can also result in a range of clinical challenges, such as a more complicated therapeutic alliance, issues pertaining to adaptive health behaviors, drug-drug interactions and adverse events induced by medications used for physical and mental disorders. Potential explanations for the high prevalence of the above comorbidity involve shared genetic and biological pathways. These latter include inflammation, the gut microbiome, mitochondrial function and energy metabolism, hypothalamic-pituitary-adrenal axis dysregulation, and brain structure and function. Furthermore, MDD and physical diseases have in common several antecedents related to social factors (e.g., socioeconomic status), lifestyle variables (e.g., physical activity, diet, sleep), and stressful live events (e.g., childhood trauma). Pharmacotherapies and psychotherapies are effective treatments for comorbid MDD, and the introduction of lifestyle interventions as well as collaborative care models and digital technologies provide promising strategies for improving management. This paper aims to provide a detailed overview of the epidemiology of the comorbidity of MDD and specific physical diseases, including prevalence and bidirectional risk; of shared biological pathways potentially implicated in the pathogenesis of MDD and common physical diseases; of socio-environmental factors that serve as both shared risk and protective factors; and of management of MDD and physical diseases, including prevention and treatment. We conclude with future directions and emerging research related to optimal care of people with comorbid MDD and physical diseases. |