Age-related hearing loss (ARHL) is the third most common health condition affecting older adults after
heart disease and arthritis and is the fifth leading cause of years lived with disability worldwide. The
prevalence of clinically significant hearing impairment rises steeply with age, from 3% among adults 20-29 to
49% of adults ages 60-69 and over 80% in individuals 85 years of age and older. Many hearing-impaired older
adults avoid or withdraw from social contexts in which background noise will make it difficult to communicate,
resulting in social isolation and reduced communication with family and friends. Social isolation and loneliness
have been linked to numerous adverse physical and mental health outcomes, including dementia, depression,
and mortality, and they may also lead to declining physical activity and the development of the syndrome of
frailty. Neuroimaging studies of ARHL have begun to elucidate the brain changes associated with degraded
auditory input that provide plausible pathways by which chronic hearing loss may cause cognitive dysfunction
and affective dysregulation. In this project we hypothesize that untreated ARHL represents a distinct
pathophysiologic route to developing Late-life Depression (LLD) and that individuals with comorbid ARHL/LLD
are unlikely to respond to treatments (i.e., antidepressant medication) that do not treat the underlying hearing
problem. Initial studies suggest remediation of hearing loss using hearing aids or cochlear implantation may
decrease depressive symptoms acutely and over the course of 6 to 12 months follow-up. However, the clinical
significance of these findings is obscured by lack of rigorous control groups, failure to objectively document
hearing aid compliance, and enrollment of study populations lacking syndromal depression or even a threshold
symptom score. We propose to conduct the first clinical trial possessing these design features, while also
incorporating neuropsychological and neuroimaging assessments that allow us to elucidate predictors and
mechanisms of treatment response. 40 individuals will be recruited who are aged =60 years, diagnosed with a
clinically significant depressive disorder, and have moderate ARHL with impaired speech discrimination.
Comprehensive baseline psychiatric, audiometric, neuropsychological, and functional assessment will be
performed in addition to structural MRI (white matter hyperintensity [WMH] estimation and grey matter
morphometry), diffusion imaging with tractography, and functional MRI (resting state connectivity within the
CCN). Participants then will be randomized to receive antidepressant medication (AD) treatment plus bilateral
hearing aids (AD + hearing aids) or antidepressant medication plus sham hearing aids (AD + sham) over a 12-
week prospective trial. The baseline evaluation, including MRI scanning, will be repeated at the study endpoint.
Data from this study could suggest a novel therapeutic strategy for LLD and thereby mitigate its public health
burden, while also contributing to the increased recognition and treatment of ARHL more generally.