‘Curious’ finding
Individuals with mental disorders showed a higher risk of medical conditions in 76 out of 90 specific mental disorder–medical condition pairs.
After adjusting for sex, age, calendar time, and previous coexisting mental disorders, the median hazard ratio for a subsequent medical condition was 1.37 in patients with a mental disorder.
The lowest HR was 0.82 for organic mental disorders and the broad category of cancer (95% confidence interval, 0.80-0.84), and the highest was 3.62 for eating disorders and urogenital conditions (95% CI, 3.11-4.22). On the other hand, schizophrenia was associated with a reduced risk of developing musculoskeletal conditions (HR, 0.87; 95% CI, 0.84-0.91).
Dr. McGrath described this finding as “curious” and speculated it “may be related to underlying genetic risk factors.”
compared with the matched reference group without a mood disorder (40.9% vs. 32.6%, respectively).
The risk of developing subsequent medical conditions after a mental disorder diagnosis did not remain steady over time. For instance, although mood disorders were associated with an increased risk of developing circulatory problems (HR, 1.32; 95% CI, 1.31-1.34), the highest risk occurred during the first 6 months following diagnosis and gradually decreased over the next 15 years (HR, 2.39; 95% CI, 2.29-2.48 and HR, 1.18; 95% CI, 1.17-1.20, respectively).
“Many people with mental disorders have unhealthy lifestyle, including low exercise, poor diet, smoking, and alcohol, which may account for the increased risk of physical illness, and also they may not seek and/or may not get quick treatment for their health conditions,” said Dr. McGrath.
Additionally, “perhaps some genetic and early life exposures, such as trauma, may increase the risk of both medical conditions and mental disorders,” he added. “We need better treatments for mental disorders, so that they do not slip into unemployment or poverty.”
A strong case
In a comment, Roger McIntyre, MD, professor of psychiatry and pharmacology at the University of Toronto and head of the mood disorders psychopharmacology unit, University Health Network, said that the research “really makes a strong case for the fact that persons who have mental disorders are at higher risk of chronic diseases, and it’s the chronic diseases that decrease their lifespan.”
Dr. McIntyre, who is also director of the Depression and Bipolar Support Alliance, said that the “takeaway message is that mental disorders are not just brain disorders but are multisystem disorders.”
For this reason, “the most appropriate way to provide care would be to provide a holistic approach to treat and prevent the chronic diseases that lead to increase in mortality,” recommended Dr. McIntyre, who was not involved with the current study.
The study was supported by grants from the Danish National Research Foundation, the National Health and Medical Research Council, the Novo Nordisk Foundation , the European Union’s Horizon 2020 Research and Innovation Program, the Aarhus University Research Foundation, the Lundbeck Foundation, the National Institutes of Health, the European Commission, Helsefonden, the Danish Council for Independent Research, the Independent Research Fund Denmark, the National Health and Medical Research Council of Australia, and the National Institute on Drug Abuse.
Dr. McGrath has disclosed no relevant financial relationships. The other authors’ disclosures are listed on the original paper. Dr. McIntyre reports receiving grants from Stanley Medical Research Institute; the Canadian Institutes of Health Research/Global Alliance for Chronic Diseases/Chinese National Natural Research Foundation; and receiving speaking/consultation fees from Lundbeck, Janssen, Shire, Purdue, Pfizer, Otsuka, Allergan, Takeda, Neurocrine, Sunovion, and Minerva.
A version of this article originally appeared on Medscape.com.