Many physical disorders, such as cardiac disease, diabetes, and various cancers, can lead to depression in older adults (Romanelli et al., 2002
; Lyles, 2001
). Functional status can also have an impact on depression (Bruce, 2001
; Zeiss et al., 1996
). Yet we have little data on how specific physical symptoms (those very presentations most often seen in the primary care physician’s office) contribute to depression.
One of the most common symptoms among older adults is shortness of breath (SoB). In the Duke Established Populations for Epidemiologic Studies of the Elderly (EPESE), over one-third of subjects reported SoB that required them to stop and rest (Cornoni-Huntley et al., 1990
). Chronic obstructive pulmonary disease (COPD; the most common cause of SoB in the elderly—about 50% with COPD report SoB) is associated with a number of adverse outcomes (Walke et al., 2007
) including physical discomfort, fatigue, problems with appetite, and anxiety in this study. All of these symptoms may contribute to depression.
In a study of over 1000 outpatients, complaints that separate depressed from non-depressed patients included sleep disturbance, multiple physical complaints, non-specific musculoskeletal complaints, back pain, SoB, and vaguely stated complaints (Gerber et al., 1992
). In another study of depressive symptoms in elderly outpatients with stable yet disabling COPD, 46% were rated as clinically depressed compared to 11% of subjects with normal lung function (Yohannes et al., 1998
). However, spirometry results and exercise tolerance (6-min walk) did not predict the depression rating. The symptom of SoB, not the actual lung function, appears to be the important correlate with depression. In yet another study (n
= 20 296), COPD comorbid with cardiovascular disease, diabetes, and hypertension had a higher risk of hospitalization and mortality than those without. Of interest, subjects with symptoms of COPD but with normal lung function had as high a risk of cardiovascular disease as those with significant impairment of lung function (Dyer et al., 1999
). These studies suggest that symptoms of COPD, regardless of the underlying pathology, appear to be important predictors of health outcomes.
In a study of older adults, some with asthma and some without, quality of life was found to be impaired in elderly with asthma, including those with demonstrable airway variability, a symptom which can be relieved with therapy (Chavannes et al., 2005
). A study of 24 patients with severe COPD (Paz-Diaz et al., 2007
) assigned 10 to pulmonary rehab and 14 to a control group. The rehab program included disease education, energy consumption techniques, relaxation, and exercise. After pulmonary rehab, there was a significant improvement in the severity of depression compared to controls. Dyspnea was significantly better. These studies suggest that the symptoms of SoB can be relieved with aggressive treatment.
In a study of 147 primary care patients, female gender, body mass index (BMI), and dsypnea were associated with depressive symptoms. Lung function, smoking behavior, age, and comorbidity were not associated (Mannino et al., 2008
). Some health problems or health behaviors are known to be associated with both difficulty breathing and depression. Smoking clearly is the major risk factor for COPD and is associated with depression (Salive and Blazer, 1993
). Myocardial infarction, a frequent precursor to congestive heart failure, is also known to increase the risk for depression (Frasure-Smith et al., 1993
We, therefore, explored the longitudinal association between SoB and depressive symptoms. We specifically asked the questions, “In a community sample of older adults, does SoB predict an increase in depressive symptoms 3 years later in controlled analyses?” and “Does shortness of breath interact with other risks for depressive symptoms synergistically?” These questions are important because older adults experience a number of chronic symptoms. Some can be potentially alleviated over time with aggressive medical therapy and others cannot. SoB is a symptom which potentially can be alleviated in older adults through aggressive therapy.