A Closer Look at Hearing Loss, Dementia, and Stigma

We’ve all had these conversations. A family member asks us, “What’s all this talk about hearing loss and dementia?” A patient comes to our clinic and says, “I heard if I get a hearing aid, I will not get dementia.” Perhaps they’ve seen a headline claiming that “hearing loss is a major risk factor for dementia” in The Washington Post1 or heard an interview on National Public Radio’s Weekend Edition Sunday explaining that hearing loss “actually affect(s) the brain’s structural integrity.” 2 Other major news outlets have run similar stories 3,4, leading many to wonder: has hearing loss already damaged my brain? Am I destined to develop dementia?www.shutterstock.com.We recently wrote an article that critiqued these media reports. Our article was published in a geriatrics journal. Given the favorable reader response we have chosen to share our thoughts with our community of hearing health care professionals. The primary point we wish to convey is that messages like “hearing loss is a risk factor for dementia” need to be changed. Not only is such messaging confusing, but such messages are also prone to stigmatize and worry people with hearing loss. We should add as well that most scientists agree that the evidence to date is unsettled. CONFUSION ABOUT RISK The message that hearing loss is “the largest potentially modifiable risk factor for dementia” comes from an epidemiologic analysis that appeared in The Lancet in 2017 and 2020. 5 The reports were primarily based on studies in which people with various degrees of hearing loss (but without cognitive impairment at the start of the study) were followed over several years. In each of the studies, people with greater hearing loss at the outset were more likely to perform poorly on cognitive tests over time. Their cognitive dysfunction was severe enough to be labeled “dementia” more often than the dysfunction found in people who did not have hearing loss at the outset. Based on the studies reviewed, a set of distinguished epidemiologists declared that hearing loss is a leading “risk factor” for dementia. But “risk” and “risk factor” have special meanings in epidemiology. Unlike in everyday English (where “risk” suggests a cause of something bad) epidemiologic risk is only about co-occurrence, or correlation. But as we all probably learned during our undergraduate or graduate studies, correlation is not causation. In other words, saying that hearing loss is a risk factor for dementia does not mean that hearing loss causes dementia. SCIENTIFIC UNCERTAINTY ABOUT THE UNDERLYING CAUSE It is important to realize that after many years of research there is very little known about the causes of Alzheimer’s disease (AD) and AD-related dementias (AD/ADRD). Given our general ignorance, it is not surprising that we lack a scientific understanding about whether and how hearing loss might be involved. Four possible explanations have been advanced. 6 The first points to the social isolation that accompanies hearing loss, because social isolation is also associated with dementia. The second emphasizes the excess cognitive load associated with poor hearing: the degraded speech signal requires greater listening effort, depleting the cognitive resources that would otherwise be used for other tasks. The third posits an unknown aging factor that damages both the brain and the peripheral ear. A final theory says that hearing loss directly triggers or somehow augments the brain degenerative changes that are seen in AD/ADRD, perhaps mediated by the temporal lobe atrophy that can accompany hearing loss. It is unknown whether one or more of these theories is correct, and this is likely to remain unclear for the foreseeable future. In other words, we don’t know what explains the hearing loss-dementia link. STIGMA The experience of stigma includes internalized shame and exclusion from the wider social world. 7 People with hearing loss face tremendous stigma 8: that is a key part of being reluctant to seek care or postponing care from a hearing health care professional. The fear of being “found out” also drives our patients’ preferences for “discreet” instruments. People with hearing loss are notably reluctant to seek assistance and accommodation (most people with hearing loss do not own hearing aids) and of course they are worried that people will treat them differently. Instead of seeking help, people feign understanding and choose to withdraw rather than struggle in social situations. People with dementia also face stigma, and the stereotypes are fierce. 9 People with dementia are often seen as incapable of making decisions, acting independently, or participating in community life. There is probably no more stigmatized common chronic condition. “Dementia worry” (fearful anticipation of a dementia diagnosis, whether that fear is warranted or not) is a source of anxiety among many adults. 10 Like hearing loss, dementia often goes undetected in primary care settings and undertreated. THE BIG MISUNDERSTANDING In our experience, when people are told that “hearing loss is the most common preventable risk factor for dementia,” they don’t understand “risk” in the epidemiologic sense. They jump to the natural, everyday language interpretation of risk that suggests that they have a high probability of developing dementia. And they are worried. Some are terrified. After reading our previously published piece, a friend with hearing loss wrote of her immense relief to learn that she was not doomed to develop dementia. She had understood the reports she’d seen in the press as saying that she would be “unlikely to be able to dodge the dementia bullet.” A shared public understanding that hearing loss foreshadows dementia would be devastating for people with hearing loss, who could be subject to greater discrimination in the workplace and social exclusion. For example, if you (mis)understood that hearing loss foreshadows dementia, would you hire an older person who wore hearing aids? Would you want your widowed mother to remarry someone who had difficulty hearing? WHY HEARING LOSS MIGHT BE ASSOCIATED WITH GREATER COGNITIVE DECLINE We know that better hearing can help people to think, remember, and learn. 11 But some people are unfortunately destined to develop dementia as they age. As that unfolds, those individuals will be more cognitively symptomatic if they also have difficulty hearing, because of the importance of hearing in thinking, remembering, and learning. The current randomized trials of hearing aids have been portrayed as tests of whether hearing loss causes dementia, or if hearing aids can prevent dementia. We think this is a mischaracterization. If those receiving hearing aids fare better cognitively in follow up, with more crossing the threshold that is labeled “dementia” over time, can we conclude that hearing loss causes dementia, or hearing aids prevent dementia? We don’t think so. An equally plausible explanation is that hearing aids can help manage cognitive disability for those who are destined to develop dementia for separate (neuropathologic) reasons. For people who are destined to develop dementia, hearing aids may improve audibility, may reduce listening effort and fatigue; and these are very important benefits, but benefits that are quite different from “preventing dementia.” LET’S CHOOSE A POSITIVE MESSAGE If members of the public understand that hearing loss or auditory processing difficulties are a prodrome for dementia, then several things could happen. Policymakers might work to improve access to hearing health care. Primary care clinicians might screen their patients for hearing loss. People might be more inclined to seek care. And that would be good! But we agree with one of our colleagues who wrote to us when he read our recent publication: “We became audiologists to help people with hearing loss find help. Not scare them into submission.” Better hearing offers tremendous benefits that we have all witnessed in our clinical work. But let’s not sell our devices as “dementia preventers,” in part because it’s not clear that’s what they actually are. In fact, they are much more: we’ve seen them help people to hear better, think better, and appreciate life more. When we talk about the cognitive benefits of hearing aids and cochlear implants, let’s give a positive message like, “Hearing better helps you to think better.” Let’s not be confusing, or stretch the facts. Let’s not stigmatize the hearing loss community. Better hearing is good for anyone, at any age. Let’s move toward a philosophy of positive messaging.