The systematic review and meta-analysis Association of hearing loss and risk of depression included 24 cohort studies from multiple countries. The authors of the study observed that many previous meta-analyses of the data linking hearing loss to depression focus on hearing loss and late-life depression, which may explain why they mostly focused on older adults. Therefore, to further our understanding, this review included studies with participants ranging from children to older adults.

The sample sizes varied from 548 to 254,466, with follow-up periods of 1 to 25 years. The included studies examined various forms of hearing loss and were evaluated through self-reports, clinical scales, medical records, and insurance claims. The research also accounted for demographics, lifestyle, health status and cognitive function.

The headline findings: age matters

The review found that individuals with hearing loss have an increased probability of developing depression compared to those without hearing loss*.

*Individuals with hearing loss had 35% higher odds (odds ratio: 1.35) of developing depression compared to those without hearing loss.

The findings of this meta-analysis suggest that hearing loss may be an independent risk factor for depression across all age groups, but the risk is highest among older adults. Hearing loss at any age can take a toll on mental health. For children, hearing loss may delay communication development, which can lead to social withdrawal – a gateway to depression in adolescence, adulthood or later life.

Similarly, communication difficulties are common in adults with hearing loss, which can lead to social isolation, ultimately resulting in depression. This finding underscores the importance of paying closer attention to hearing loss in all age groups, including children.

Explaining the link: correlation vs. causation

The risk of depression in individuals with hearing loss is well-supported by evidence. But explanations of the risk are still hypothetical.

One hypothesis is emotion-based. Loneliness and social isolation are two examples of negative emotions that can come in tandem with hearing impairment, which may contribute to an increased risk of depression.

Another suggestion is that the reduced auditory input for individuals with hearing loss can cause a loss of tissue in the brain's thinking and control regions, meaning hearing loss could be to blame for accelerated brain trophy and, in some cases, shrinkage.

Finally, one potential mechanism linking hearing loss to a greater risk of depression is a weaker emotional response in the brain regions involved in emotional processing and memory when hearing emotional sounds. This diminished response may make it harder to fully process emotional experiences, which may increase the risk of loneliness and social isolation, that can contribute to depression.

Hearing loss: more than a sense

Fortunately, we live in a time when mental health is taken more seriously than ever before. These fresh insights around hearing loss and depression across age groups emphasise the importance of prevention and early intervention, not just for the sake of protecting hearing, but wellbeing too.

Hearing loss is clearly more than a deterioration of auditory function; it carries a mental health risk for people of all ages. Meta-analyses like this one expand our understanding of the broader health implications of hearing loss, helping us base our work in a solid understanding of the audiology landscape. The more we know about the broader risks of hearing loss, the better we can advocate for better hearing health care worldwide.

The broader story

Mental health isn't the only dimension of health impacted by hearing loss. The connection between hearing loss and cognitive function is well-established, particularly in older populations. However, recent research has suggested that earlier intervention may impact cognitive health outcomes to a greater extent than previously realised.

Read The Case for Mid-Life Hearing Care to learn more about the importance of shifting the timeline of hearing care earlier.