The architecture of co-morbidity networks of physical and mental health conditions in military veterans

• Published in: Proceedings of the Royal Society. A, Mathematical, physical, and engineering sciences Mathematical, physical, and engineering sciences, 2020-07, Vol.476 (2239), p.20190790-20190790
• Main Authors: Alexander-Bloch, Aaron F, Raznahan, Armin, Shinohara, Russell T, Mathias, Samuel R, Bathulapalli, Harini, Bhalla, Ish P, Goulet, Joseph L, Satterthwaite, Theodore D, Bassett, Danielle S, Glahn, David C, Brandt, Cynthia A
• Format: Article
• Language: English
• ISSN: 1364-5021; 1471-2946
• DOI: 10.1098/rspa.2019.0790

Co-morbidity between medical and psychiatric conditions is commonly considered between individual pairs of conditions. However, an important alternative is to consider all conditions as part of a co-morbidity network, which encompasses all interactions between patients and a healthcare system. Analysis of co-morbidity networks could detect and quantify general tendencies not observed by smaller-scale studies. Here, we investigate the co-morbidity network derived from longitudinal healthcare records from approximately 1 million United States military veterans, a population disproportionately impacted by psychiatric morbidity and psychological trauma. Network analyses revealed marked and heterogenous patterns of co-morbidity, including a multi-scale community structure composed of groups of commonly co-morbid conditions. Psychiatric conditions including posttraumatic stress disorder were strong predictors of future medical morbidity. Neurological conditions and conditions associated with chronic pain were particularly highly co-morbid with psychiatric conditions. Across conditions, the degree of co-morbidity was positively associated with mortality. Co-morbidity was modified by biological sex and could be used to predict future diagnostic status, with out-of-sample prediction accuracy of 90-92%. Understanding complex patterns of disease co-morbidity has the potential to lead to improved designs of systems of care and the development of targeted interventions that consider the broader context of mental and physical health.