By Chuan-Ming Li, MD, PhD, & Howard J. Hoffman, MA
Dr. Li, left, is statistician (health/medicine) and Mr. Hoffman is director of the Epidemiology and Statistics Program, Division of Scientific Programs, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health (NIH). Dr. Li performs analyses for epidemiological studies and reviews concept proposals for NIDCD clinical trials.
Hearing loss is the third-leading cause of years lost due to disability worldwide. (The Global Burden of Disease: 2004 Update. Geneva, Switzerland: World Health Organization [WHO]; 2008.) An estimated 299 million men and 239 million women globally have moderate or worse hearing loss, Gretchen Stevens and colleagues reported on behalf of the 2010 Global Burden of Disease Hearing Loss Expert Group (Eur J Public Health 2013;23[1]:146-152).
Even more common, however, is depression. In the WHO report, unipolar depression occupied first place for years lost due to disability worldwide. The burden of depression is 50 percent higher for women than men.
We and our colleagues recently reported on the relationship between depression and hearing loss using the National Health and Nutrition Examination Survey (NHANES), 2005-2010, which includes a nationally representative sample of the civilian, noninstitutionalized population (JAMA Otolaryngol Head Neck Surg 2014;140[4]:293-302).
The prevalence of moderate-to-severe depression was significantly higher among adults age 18-69 who had self-reported hearing loss (11.4%) compared with those who reported good-to-excellent hearing (5.9%). The prevalence of depression rose as the degree of reported hearing loss increased from a little trouble, to moderate trouble, to a lot of trouble hearing, but not for individuals self-identified as deaf.
No relationship between depression and self-reported hearing loss was found among adults age 70 and older. In women 70 and older, there was a significant association between depression and an exam-based measure of moderate hearing loss (better ear [BE] pure-tone average [PTA] of 35-50 dB HL), but not in men of that age group.
These paradoxical results may reflect the tendency of people in different age groups to assess their hearing loss in distinct ways.
For example, older adults may be less likely than younger adults to self-report hearing loss in relation to activity limitations. While men begin experiencing hearing loss in midlife, perhaps due to noise exposure, onset in women occurs 15 to 20 years later, typically around age 70.
Hearing loss is much more common than vision loss among older adults, as Vincent A. Campbell et al demonstrated (MMWR CDC Surveill Summ 1999;48[8]:131-156). Also, coping with hearing loss is different from dealing with other disabilities, since hearing loss is an invisible condition, frequently unrecognized by healthcare professionals.
The Seniors Research Group characterized the impact of hearing loss as often profound, with consequences for a person’s social, functional, and psychological well-being, as well as overall health, since hearing loss isolates people from friends and family because of a decreased ability to communicate. (The Consequences of Untreated Hearing Loss in Older Persons. Washington, DC: National Council on Aging; 1999.)
What can people with hearing loss do to avoid depression? We suggest they seek hearing healthcare and consider joining national organizations for people with hearing loss. When recommended, rehabilitation via hearing aids, alternative listening devices, etc. may assuage the difficult personal and social adjustments that attend hearing loss.
Health professionals can improve identification through regular hearing screening. The quality of life of people with hearing loss can be made better if doctors recognize the signs and symptoms of depression and refer patients for mental health services.
While treatment can help the majority of people with depressive illness, even those with the most severe depression, many people do not seek it. Effective treatments for depression include medication, psychotherapy, and other methods.
Although the mechanism connecting hearing loss with depression is unclear, the association between the two conditions suggests that treating people who have hearing loss at early stages may reduce their risk of developing depression.