Living with major depressive disorder (MDD) reduces life expectancy, with respiratory disease being a significant threat. However, evidence on respiratory disease in this population has not yet been meta-analyzed.

This meta-analysis examines respiratory disease prevalence and odds ratio (OR) in patients with MDD and treatment resistant depression (TRD). A systematic literature search was conducted, with a snowball search of reference and citation lists. Inclusion criteria covered studies in MDD and TRD patients with confirmed diagnoses of respiratory diseases (asthma, chronic obstructive pulmonary disease [COPD], pneumonia, lung cancer, and tuberculosis), comparing with a control group when possible.

From 4,138 retrieved articles, 15 (including 476,927 individuals with MDD, 50,680 with TRD, and 1,108,979 control group) met the inclusion criteria. In MDD patients, COPD prevalence was 9.0% (95% CI: 3.8–19.6%), asthma 8.6% (95% CI: 5.7–12.8%), and pneumonia 2.5% (95% CI: 2.2–2.9%). In TRD patients, COPD prevalence was 9.9% (95% CI: 4.2–21.9%) and asthma 10.9% (95% CI: 10.7–11.2%), but meta-analysis limited to those diseases showed no significant relative risk differences. Compared to the general population, individuals with MDD had significantly higher rates of COPD (OR 1.79, 95% CI: 1.49–2.16), even higher in younger populations (1.85 [95% CI: 1.74–1.97]) and more prevalent in women.

This first meta-analysis on this topic shows that MDD is associated with an increased risk of respiratory illness compared to the general population. The prevalence of asthma doubles the mean described in the general population worldwide, and in COPD, women and younger people are at particular risk. Prevention policies are urgently needed.

Thousands of rescue and recovery workers descended on the World Trade Center (WTC) in the wake of the terrorist attack of September 11, 2001 (9/11). Recent studies show that respiratory illness and post-traumatic stress disorder (PTSD) are the hallmark health problems, but relationships between them are poorly understood. The current study examined this link and evaluated contributions of WTC exposures.

Participants were 8508 police and 12 333 non-traditional responders examined at the WTC Medical Monitoring and Treatment Program (WTC-MMTP), a clinic network in the New York area established by the National Institute for Occupational Safety and Health (NIOSH). We used structural equation modeling (SEM) to explore patterns of association among exposures, other risk factors, probable WTC-related PTSD [based on the PTSD Checklist (PCL)], physician-assessed respiratory symptoms arising after 9/11 and present at examination, and abnormal pulmonary functioning defined by low forced vital capacity (FVC).

Fewer police than non-traditional responders had probable PTSD (5.9% v. 23.0%) and respiratory symptoms (22.5% v. 28.4%), whereas pulmonary function was similar. PTSD and respiratory symptoms were moderately correlated (r=0.28 for police and 0.27 for non-traditional responders). Exposure was more strongly associated with respiratory symptoms than with PTSD or lung function. The SEM model that best fit the data in both groups suggested that PTSD statistically mediated the association of exposure with respiratory symptoms.

Although longitudinal data are needed to confirm the mediation hypothesis, the link between PTSD and respiratory symptoms is noteworthy and calls for further investigation. The findings also support the value of integrated medical and psychiatric treatment for disaster responders.