Depression might be more harmful than the other chronic diseases that can strike elderly people, a new study claims.

Even though heart and lung disease can take their toll on seniors, it is the accompanying depression that can most affect their quality of life, University of Texas researchers found.

Fortunately, seniors can improve their quality of life with diagnosis and treatment despite having debilitating physical conditions, according to the report in the November/December issue of the Annals of Family Medicine.

“Depression can have a devastating impact on general functioning and quality of life,” said study author Polly Hitchcock Noël, an assistant professor of medicine at the University of Texas Health Science Center at San Antonio. “Depression is a treatable disease; and treatment may have the potential to improve quality of life and overall functioning, despite the presence of other chronic illnesses.

“In our study, we looked at four measures of health status, including disability, quality of life, mental functioning, and general health functioning,” Noël explained. The severity of depression was the only thing that was significantly associated with all the health status outcomes, she said.

Noël’s team collected data on 1,801 patients aged 60 and older who were diagnosed with major depression. These patients also had other diseases, including chronic lung disease, high blood pressure, diabetes, arthritis, cancer, heart disease, chronic pain, gastrointestinal disease, and urinary or prostate disease.

“Eight of the illnesses were more associated with physical activity than depression,” Noël said. “However, depression made a larger contribution to mental health function, disability, and quality of life than the other medical variables.”

Based on her study and others, Noël believes that depression contributes to general quality of life, disability, and mental functioning. “Treatment for depression has the potential to greatly impact overall health outcomes for primary-care patients over and above the relief of medical symptoms,” she said.

Noël’s team found that patients who received treatment for depression showed an improvement in quality of life and were less impaired and less debilitated, compared with patients who did not receive treatment.

According to Noël, a problem that exists throughout the United States is that depression is not often recognized by primary-care providers. “Even when it is recognized, it often receives suboptimal treatment,” Noël added.

“This is an important study of a large group of primary-care patients, conducted by a well-recognized group of investigators,” said Dr. Jeffrey M. Lyness, director of the Program in Geriatrics and Neuropsychiatry at the University of Rochester Medical Center.

The study confirms and extends previous research demonstrating that depressive symptoms are powerfully associated with poor quality of life in older patients, even more so than the chronic physical conditions that are common in older patients and are often disabling themselves, he added.

“The good news is that this means that improved recognition and treatment of depressive symptoms holds promise to improve functioning and quality of life for many seniors,” Lyness said.