Dr Ruan-Ching Yu: dementia and hearing loss

What inspired you to take a closer look at the relationship between hearing loss severity and dementia?

In my work at the intersection of psychiatry and audiology at UCL, I kept hearing the same story: when hearing fades, conversations become exhausting, social life shrinks, and thinking feels harder. That pattern didn’t feel incidental. I wanted to know not just whether hearing loss matters for dementia risk, but how much it matters. Colleagues across the Ear Institute and the Division of Psychiatry - especially my manager, Professor Sergi Costafreda Gonzalez, and my mentor, Professor Anne G. M. Schilder - and our PPI contributors encouraged me to test that question rigorously: does risk increase with severity, and could earlier, simpler support reduce the risk? Synthesising the best available evidence felt like the most reliable way to answer it and to inform both clinical practice and policy.

Tell us more about your project and your findings.

This project was a systematic review and meta-analysis of more than 1.5 million participants across 50 longitudinal cohort studies, examining hearing loss and cognitive outcomes. We quantified a clear dose–response relationship between hearing-loss severity and dementia risk.

Both mild and moderate-to-severe hearing loss were associated with higher dementia risk, and each 10‑decibel worsening of hearing was linked to a 16% increase in risk—showing that even modest declines matter. In short, the greater the hearing loss, the higher the risk of dementia. This shifts the conversation from “Does hearing loss matter?” to “How much does it matter—and what can we do about it?”

Tell us about the wider collaborative programme that you are part of.

This research underpins TACT+ (Treating Auditory Impairment to Preserve Cognition in People with Mild Cognitive Impairment), an NIHR Stage 1–selected research programme now progressing through Stage 2 review. TACT+ brings together specialists in psychiatry, audiology, general practice, and public-health implementation science to develop and evaluate hearing-care interventions for people with mild cognitive impairment (MCI)—a group at higher risk of dementia. These include timely access to hearing aids, personalised support, and coordinated follow-up. Contributing to such a multidisciplinary effort is a privilege. Our shared goal is to deliver practical, scalable solutions that improve real-world outcomes for people at risk of cognitive decline.

How do you see your findings influencing clinical practice or public health policy in future?

Our meta-analysis shows that hearing loss is consistently linked with a higher risk of dementia. While observational data alone cannot prescribe specific clinical actions, they highlight hearing care as an important - and potentially modifiable - element of dementia‑risk reduction. The work underlines the need to assess hearing routinely when people present with memory concerns and to study whether timely intervention makes a difference.

At a public‑health level, the evidence strengthens the case for investing in accessible, evidence‑based hearing services for older adults. If funded, the TACT+ randomised controlled trial (currently under NIHR Stage 2 review) will provide the prospective data needed to guide future guidelines and policy on proactive dementia prevention.

What are the next steps for this research? Are there any follow-up studies or new directions you’re excited about?

The next step is a large‑scale RCT within TACT+ (under review) to test the effectiveness of hearing interventions in reducing cognitive decline among people with MCI. We’re also exploring how these interventions can be delivered more equitably, including via telehealth and community‑based models.

Personally, I’m interested in understanding not just whether hearing care works, but how it works - and for whom - so we can make interventions more person‑centred and impactful in real‑world settings.