LOS ANGELES – Strong associations exist between depression and chronic medical comorbidities in older adults, according to an analysis of 2009-2010 data from the National Health and Nutrition Examination Survey.
The findings have important implications for treating the aging ill, Dr. Margaret A. Ege reported in a poster at the annual meeting of the American Association for Geriatric Psychiatry.
Among the 2,063 adults aged 60 years and older from the 2009-2010 National Health and Nutrition Examination Survey (NHANES), 5% had major depression and 72.9% had at least one chronic medical comorbidity, including osteoporosis, arthritis, coronary artery disease, gout, diabetes, stroke, asthma, chronic obstructive pulmonary disease (COPD), and congestive heart failure. The prevalence of depression was only 1.2% in those with no medical comorbidities, compared with 5.9% in those with at least one comorbidity, according to Dr. Ege of the University of Arkansas for Medical Sciences, Little Rock.
After adjustment for age, race, and gender, the odds ratio for depression in those with one or more comorbidities was 3.4.
The prevalence of depression by medical comorbidity was 7.4% for osteoporosis, 7.1% for arthritis, 7.5% for coronary artery disease, 6.7% for gout, 9.3% for diabetes, 8.9% for stroke, 10% for asthma, 11.9% for COPD, and 11.7% for congestive heart failure.
NHANES participants were screened using questions derived from the nine-item Patient Health Questionnaire (PHQ-9), along with additional questions about multiple medical comorbidities.
"When using a conservative cut-off to make a diagnosis of depression, individuals with arthritis, congestive heart failure, COPD, asthma, and diabetes were all significantly more likely to be depressed. When using a less stringent cut-off, individuals post stroke were also significantly more likely to be depressed," Dr. Ege explained, noting that, in general, higher numbers of chronic medical illnesses were associated with a higher prevalence of comorbid depression.
The findings are important, given the high prevalence of both depression and chronic medical illness in older adults. By some estimates, more than 10% of adults over age 60 years and nearly a third of older adults in residential care meet DSM-IV criteria for major depressive disorder. Even higher rates have been reported among those in nursing homes.
"Many patients and care providers assume that depression is a normal part of aging or a normal consequence of chronic medical illness, leading to less emphasis placed on the diagnosis and treatment of depression in older adults," Dr. Ege wrote.
Depression, however, has been shown to increase mortality in medical conditions such as COPD, end-stage renal disease, and coronary artery disease, she added.
Although the current findings are limited by the cross-sectional nature of the NHANES data and by the self-report of medical comorbidities – which precludes any determination about causality with respect to depression and medical comorbidities – they do suggest a strong association between the two and they underscore the importance of implementing depression screenings in medical clinics, particularly in patients with chronic medical conditions, she concluded.
Dr. Ege had no disclosures.