such as "Introduction", "Conclusion"..etc
It is well known that patients with
chronic obstructive pulmonary disease (COPD) frequently suffer from depression
and anxiety, but according to new research, depression and anxiety may actually
cause increased hospitalizations and exacerbations.
“This is an important and revealing
finding, indicating that for COPD patients, depression and anxiety must be
treated as potential clinically important risk factors, rather than simple
comorbidities that are caused by COPD,” said principle investigator of the
paper, Jean Bourbeau, M.D., director of the Respiratory Epidemiology and
Clinical Research Unit of McGill University, in Montreal.
To determine whether depression and
anxiety were independent risk factors for COPD exacerbations and
hospitalizations, the researchers prospectively recruited nearly 500 patients
with stable COPD from ten hospitals in Beijing. Each patient was assessed at
baseline for anxiety and depression as well as disease severity. They were
contacted monthly by telephone for one year to determine whether they had
experienced any exacerbations or hospitalizations.
“Almost a quarter of the patients we
monitored were suspected of having depression at baseline (13.8 percent possible
and 9 percent probably cases), and nearly one in ten were suspected of having
anxiety (4.5 percent possible and 5.1 percent probable cases),” said Dr.
Depressed patients had a higher
proportion of concurrent anxiety than non-depressed patients. They also had
higher mortality, more symptom- and event-based exacerbations and
hospitalizations and longer hospital stays than non-depressed patients. They
were also more likely to have had past exacerbations and hospitalizations.
Hospital stays were nearly two and a half times as long for depressed patients,
although the association did not reach statistical significance.
Anxiety was also associated with a
greater risk of exacerbations and longer hospital stays. Overall, among patients
with anxiety who had at least one exacerbation, the exacerbation lasted nearly
twice as long as those without anxiety, but there was no support for previous
findings that hospitalizations were affected by anxiety in length or
Because these effects were evident after
adjustments for all known confounding factors using a causal diagram, and
because the outcomes were measured after psychological exposures, the
researchers assert that not only is depression linked to greater risk
of more and lengthier COPD exacerbations and hospitalizations, but that their
findings suggest a causal relationship.
“To our knowledge this is the first
report of the possible causal association between depressive symptoms and
exacerbations and hospitalizations in stable COPD. However, people have to
realize that the causal relationship is a complicated issue and will require
further evaluation as part of other properly designed longitudinal studies,”
wrote Dr. Bourbeau.
While they acknowledge that there may
have been a differential loss of depressed/non-depressed patients in follow up,
because patients who withdrew earlier had more severe COPD and were more
depressed than those who completed follow-up, it is likely that the association
was underestimated than anything. “Similarly, the association between anxiety
and exacerbations may have been underestimated due to the differential
attrition,” said Dr. Bourbeau.
The researchers proposed a number of
possible explanations for their findings—that depression itself may effect
changes in the immune system; that depression affects patients’ ability to adapt
to chronic symptoms, thereby making them more likely to make frequent visits to
the doctor and receive pharmacological treatment; or depression may decrease
self-confidence and increase feelings of hopelessness, resulting in poorer
self-care and poorer medication compliance.
“The results of this study can guide
researchers and clinicians to evaluate in COPD patients with depression the
effectiveness of antidepressants and psychotherapies on reducing exacerbations
and related complications such as hospital admissions,” concluded Dr.
News release courtesy of American Thoracic Society on October 24, 2008.
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