Neural Effects of Hearing Loss and Hearing Aids in Late-Life Depression

Abstract

<h3>Introduction</h3> Age-related hearing loss (ARHL) has been associated with the development of late-life depression (LLD). However, no prospective, randomized controlled trial of hearing treatment for individuals with ARHL/LLD incorporating comprehensive neuropsychiatric assessments and multimodal neuroimaging has been performed previously. <h3>Methods</h3> Double-blind randomized controlled trial of hearing aids for individuals aged ≥60 years with a depressive disorder and at least moderate hearing loss (as defined by Pure Tone Average > 50dB). Participants are randomized to full-amplitude hearing aids or low-amplitude (i.e., sham) hearing aids for 12-weeks as an augmentation to antidepressant medications. Primary outcomes include depressive symptoms (Hamilton Rating Scale for Depression [HRSD]), hearing status (Hearing Handicap Inventory for the Elderly [HHIE]), cognitive functioning (Repeatable Battery for the Assessment of Neuropsychological Status [RBANS]), and social functioning (Social Adjustment Scale - Self Report [SAS-SR]), as well as connectivity/activation within the cognitive control network on a response inhibition/interference (Simon) task. <h3>Results</h3> As the study is ongoing, data is reported for the combined sample (full- and low-amplitude groups) to preserve blinding. However, the between group analyses will be available for presentation at the AAGP Annual Meeting. Over the 12 weeks, significant improvements have been observed on HHIE and HRSD scores (-6.9, ES=0.7, p=0.01 and -7.0, ES=1.4, p=0.002; respectively), SAS-SR (+0.27, ES=0.7, p=0.003), immediate (+9.2, ES=0.6, p=0.005) and delayed memory (+4.4, ES=0.3, p=0.006). Behavioral data for N=13 participants completing the Simon task show significantly slower reaction times (RT, 772.3 vs. 701.6ms, p<0.001) and lower accuracy (92.7 vs. 95.8%, p=0.015) on incongruent vs. congruent trials. Significant task-related activations on this contrast are present in the basal ganglia, dorsolateral prefrontal cortex, and supramarginal gyrus (voxelwise p<0.01, cluster size > 100). <h3>Conclusions</h3> Combination therapy of hearing aids and antidepressant medications may result in improvement in depressive symptoms, cognition, and social functioning among individuals with ARHL and LLD. Further studies are needed to evaluate if hearing remediation can reverse the neuroplastic changes associated with chronic ARHL. <h3>Funding</h3> 5T32MH020004-22: Research Training in Late-Life Neuropsychiatric Disorders