Many people are aware that their hearing has deteriorated but are reluctant to seek help. Perhaps they don’t want to acknowledge the problem, are embarrassed by what they see as a weakness, or believe that they can “get by” without using hearing aids. And, unfortunately, too many people wait years before getting treatment.
The psycho-social issues associated with hearing loss have been known for decades. In 1999, the National Council on the Aging published the results of a study that showed the effects of untreated hearing loss. Specifically the study linked untreated hearing loss to
• irritability, negativism and anger;
• fatigue, tension, stress and depression;
• avoidance or withdrawal from social situations;
• social rejection and loneliness;
• reduced alertness and increased risk to personal safety;
• impaired memory and ability to learn new tasks;
• reduced job performance and earning power;
• diminished psychological and overall health.
Now a study by John Hopkins University School of Medicine and National Institute on Aging suggests that seniors with hearing loss are significantly more likely to develop dementia over time than those who retain their hearing.
“Researchers have looked at what affects hearing loss, but few have looked at how hearing loss affects cognitive brain function,” says study leader Frank Lin, M.D., Ph.D., assistant professor in the Division of Otology at Johns Hopkins University School of Medicine.
The researchers found that study participants with hearing loss at the beginning of the study were significantly more likely to develop dementia by the end. Compared with volunteers with normal hearing, those with mild, moderate and severe hearing loss had twofold, threefold and fivefold, respectively, the risk of developing dementia over time. The more hearing loss they had, the higher their likelihood of developing dementia.
Even after the researchers took into account other factors that are associated with risk of dementia, including diabetes, high blood pressure, age, sex and race, the study found that hearing loss and dementia were still strongly connected.
It is important to point out that the reason for the link between the two conditions is unknown. The investigators suggest that a common pathology may underlie both or that the strain of decoding sounds over the years may overwhelm the brains of people with hearing loss, leaving them more vulnerable to dementia. They also speculate that hearing loss could lead to dementia by making individuals more socially isolated, a known risk factor for dementia and other cognitive disorders.
Whatever the cause, the scientists report may offer a starting point for interventions — even as simple as hearing aids — that could delay or prevent dementia by improving patients’ hearing.