Neural and Cognitive Effects of Hearing Loss in Treatment-Resistant Late-Life Depression

Abstract

<h3>Introduction</h3> Recent research has revealed the important neuropsychiatric and brain consequences of hearing loss (HL) in older adults. Both HL and treatment-resistant late-life depression (LLD) have been demonstrated to be significant risk factors for cognitive decline and dementia. While studies have evaluated the pair-wise links between HL, LLD, and cognitive impairment, no study has evaluated the neural and cognitive effects of HL in a population with LLD. <h3>Methods</h3> Data was utilized from the OPTIMUM study, a large ongoing multicenter clinical trial recruiting older adults with LLD who have failed two or more antidepressant treatments, who are randomized to different antidepressant treatment groups. OPTIMUM-Neuro is enrolling a subset of the original OPTIMUM cohort to conduct longitudinal neurocognitive assessments and advanced neuroimaging. Pure tone audiometric hearing assessments were also performed on a subset of participants enrolled in OPTIMUM-Neuro. Among the treatment resistant LLD population in OPTIMUM-Neuro, we hypothesized that the presence of HL (pure tone average [PTA]) would be associated with greater impairment on cognitive (executive function and episodic memory) and structural brain (cortical thickness of primary and secondary auditory cortex and volume of hippocampus) outcomes at study baseline. <h3>Results</h3> Data is reported for a sample of N=126 that have been analyzed to-date, of whom N=42 have structural MRI data available. However, we aim to analyze N=200 participants (we currently have N=183 participants with hearing data) by the ACNP annual meeting. Among the sample analyzed to-date, 47.6% participants have HL and unfortunately only 30.0% participants with HL reported wearing hearing aids. At baseline, worse PTA was associated with auditory cortical thinning (R superior temporal sulcus [β=-0.0058, t=-2.57, p=0.0145]; R supramarginal gyrus sulcus [β=-0.00415, t=-2.44, p=0.0198]; R superior parietal cortex [β=-0.00474, t=-2.31, p=0.0296],) but no effect on hippocampal volume was found (R hippocampus [β=5.601, t=0.96, p=0.342]; L hippocampus [β=-0.509, t=-0.09, p=0.927]). At baseline, worse PTA was associated with impairment in executive functioning (Task switching [β= -0.054, t=-2.00, p=0.047]), visuospatial/constructional abilities (β=-0.21, t=-2.29 p=0.024]) and higher dementia rating (Clinical Dementia Rating Scale [β=0.21, t=2.77, p=0.007]), but no effect of PTA on other cognitive domains was found. <h3>Conclusions</h3> In a sample with treatment resistant LLD, HL was associated with atrophy of the primary and secondary auditory cortex and worse performance on assessments of executive functioning. Despite these adverse neuropsychiatric and brain effects of HL, it is unfortunate that hearing aids are infrequently utilized. <h3>This research was funded by</h3> Leon Levy Foundation