Chronic Respiratory Disease, Comorbid Psychiatric Disorders, and Mortality

Among patients admitted to the hospital for chronic respiratory diseases and other chronic health conditions, mortality and morbidity may be improved by identifying and treating patients’ substance use disorders and depression. This was among the findings of a study recently published in PLoS Medicine.

Although individuals with noncommunicable diseases have elevated rates of premature mortality, the contribution of psychiatric comorbidity is uncertain. Therefore, researchers sought to determine the risk for premature mortality and suicide in people with common noncommunicable diseases, with and without psychiatric disorder comorbidity.

Toward that end, researchers used national registers in Sweden to investigate over 1 million patients born between 1932 and 1995 and diagnosed with chronic respiratory diseases (n=249,825), cardiovascular diseases (n=568,818), and diabetes (n=255,579) for risks of premature mortality and suicide until December 31, 2013. Patients diagnosed with either chronic respiratory diseases, cardiovascular diseases, or diabetes were compared with age and sex-matched population controls (n = 10,345,758) and unaffected biological full siblings (n = 1,119,543).

Comorbidity with any psychiatric disorder, and by major psychiatric categories, was examined using diagnoses from patient registers. Associations were quantified using stratified Cox regression models that accounted for time at risk, measured sociodemographic factors, and unmeasured familial confounders via sibling comparisons.

The investigators found that within 5 years of diagnosis, at least 7% (range, 7.4% to 10.8%; P <.001) of patients with respiratory diseases, cardiovascular diseases, or diabetes (median age at diagnosis: 48 to 54 years) had died from any cause, and that 0.3% had died from suicide. The researchers also found that 25% to 32% of people with these medical conditions had co-occurring lifetime diagnoses of any psychiatric disorder, most of which antedated the medical diagnosis.

Comorbid psychiatric disorders were associated with higher all-cause mortality in those with chronic conditions (15.4% to 21.1%) vs without such conditions (5.5% to 9.1%). Suicide mortality was also elevated (1.2% to 1.6% in comorbid patients vs 0.1% to 0.1% in those without comorbidity). When the researchers compared relative risks with siblings without noncommunicable diseases and psychiatric disorders, the comorbidity with any psychiatric disorder was associated with substantially increased mortality rates (adjusted hazard ratio range: 7.2 for chronic respiratory diseases [95% CI, 6.8-7.7; P <.001] to 8.9 for chronic cardiovascular diseases [95% CI, 8.5-9.4; P <.001]). Notably, higher mortality was associated with comorbid substance use disorders vs depression, but risks of suicide were similar for these 2 psychiatric comorbidities.

The researchers concluded, “In this longitudinal study of over 1 million patients with chronic health diseases, we observed increased risks of all-cause and suicide mortality in individuals with psychiatric comorbidities.” They added, “Improving assessment, treatment, and follow-up of people with comorbid psychiatric disorders may reduce the risk of mortality in people with chronic noncommunicable diseases.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Sariaslan A, Sharpe M, Larsson H, Wolf A, Lichtenstein P, Fazel S. Psychiatric comorbidity and risk of premature mortality and suicide among those with chronic respiratory diseases, cardiovascular diseases, and diabetes in Sweden: a nationwide matched cohort study of over 1 million patients and their unaffected siblings. PLoS Med. 2022;19(1):e1003864. doi:10.1371/journal.pmed.1003864