As we age, our senses gradually decline, causing problems that are more than just inconveniences. Many seniors find it harder to see clearly, hear conversations, or even smell familiar odors. And new research shows that these declines in senses can impact our mental health. Led by researchers at the University of Chicago Medicine and published in the Journal of the American Geriatrics Society, the study found that older adults with sensory impairments are more likely to have poorer mental health.
The motivation behind this study stems from growing concern about aging societies and the challenges they face. The World Health Organization predicts that the global population over the age of 60 will nearly double by 2050. In the United States, nearly all older adults experience some sensory impairment, with approximately 67% having problems with two or more senses. Despite the prevalence of these issues, the relationship between sensory impairment and mental health in older adults has been underexplored, especially in the United States.
A research team led by Dr. Jayanto Pinto, an expert in smell disorders, and Alexander Wang, a medical student at the University of Chicago Pritzker School of Medicine, aimed to fill this gap: They sought to understand how sensory disorders of hearing, vision, and smell affect mental health issues such as depression, anxiety, perceived stress, and loneliness.
To explore the relationship between sensory impairment and mental health, the researchers leveraged data from the National Social Life, Health, and Aging Project (NSHAP), a nationally representative longitudinal study of older adults in the U.S. This dataset is particularly valuable because it contains detailed information about sensory function and mental health for up to 10 years, allowing researchers to track changes and outcomes over time.
The study focused on three types of sensory impairments: hearing, vision, and smell (smell). Sensory function was assessed during multiple data collection rounds, with trained interviewers rating participants' hearing and vision on a scale from “essentially deaf/blind” to “normal,” and assessing smell using a validated odor discrimination test. These ratings were used to classify participants as having a sensory impairment if their function fell below certain thresholds.
Mental health outcomes were measured using a range of validated tools, including self-rated mental health, depressive symptoms, perceived stress, anxiety and loneliness. These measures provided a comprehensive overview of participants' mental health and enabled researchers to explore associations between sensory impairment and specific mental health problems.
The researchers also took into account several other factors that may affect mental health, including age, sex, race, ethnicity, education level, marital status, alcohol consumption, smoking habits, and overall physical health. By controlling for these variables, they hoped to isolate the effect of sensory impairment on mental health.
As expected, older adults with a greater number of sensory disorders were more likely to report poorer mental health, but the type of sensory disorder also played an important role in determining what specific mental health problems they were likely to experience.
For example, visual impairment was strongly associated with poorer self-rated mental health and increased loneliness. This finding suggests that not being able to see clearly can lead to social isolation and less overall life satisfaction. Hearing impairment, on the other hand, was not as strongly associated with any specific mental health condition in this study, but did show a trend toward being associated with poorer self-rated mental health and loneliness.
Interestingly, although smell loss was not significantly associated with any specific mental health outcomes, previous research has suggested an association between smell loss and symptoms of depression and anxiety. The researchers speculated that the “invisible” nature of smell loss – meaning it is difficult for others to notice – may contribute to its weaker association with mental health outcomes compared to hearing and vision loss.
“We found that hearing and vision impairments tend to be associated with poorer self-rated mental health and loneliness, but smell impairments showed a weaker association,” Wang said. “This struck me because hearing and vision impairments tend to be much more stigmatized than smell impairments. This led me to think that social stigma may be contributing to poor mental health.”
One notable finding was that although sensory impairment was associated with self-rated mental health and feelings of loneliness, it did not significantly increase the risk of depressive symptoms, perceived stress, or anxiety when sensory impairment was considered in isolation. However, if participants had multiple sensory impairments, their risk of developing depressive symptoms increased, highlighting the cumulative impact of sensory loss on mental health.
“When your senses weaken, you experience the world less well,” Pinto says. “You may not be able to hear your colleagues or friends at the dinner table, you may not understand what's going on around you, you may have trouble reading or understanding things in your neighborhood. The cognitive burden gradually increases, and over time it will probably become exhausting and contribute to mental health issues.”
Although this study provides insight into the relationship between sensory impairment and mental health in older adults, it is not without limitations. One major limitation is its reliance on subjective assessments of hearing and vision, which may not capture subtle changes in sensory function as accurately as objective measures. Additionally, the study does not include data on when participants first experienced sensory impairments, which may influence the impact of these impairments on mental health over time.
The study, “Types of Sensory Impairment Are Differentially Associated with Mental Health Among Older Americans Over Time,” was authored by Alexander Z. Wang, Kristen E. Wroblewski, Louise Hawkley and Jayant M. Pinto.
