Depression risk after cochlear implantation compared with other rehabilitation strategies in severe hearing loss: a nationwide cohort study

Hearing loss is a growing public health concern with substantial psychosocial consequences. This study investigated whether auditory rehabilitation, particularly cochlear implantation, reduces the long-term risk of depression in individuals with severe hearing loss. Using data from the Korean National Health Insurance System from 2002 to 2020, adults aged 20–69 years with severe hearing loss (bilateral ≥ 70 dB HL) were categorized into three groups: cochlear implant (CI), hearing aid (HA), and no rehabilitation (NR). A control group without hearing loss was included. Depression incidence was tracked through 2020. The cohort included 831,042 individuals: 661 in the CI group, 15,939 in the HA group, 5,039 in the NR group, and 809,403 controls. Depression occurred in 13.6%, 18.2%, 21.9%, and 15.9% of these groups, respectively. After adjusting for confounders, all hearing loss groups had a higher depression risk than controls, with a progressive increase from CI to HA to NR. Compared to the CI group, the NR group showed a 1.3-fold higher risk of depression (95% confidence interval 1.051–1.615). These findings highlight the mental health benefits of auditory rehabilitation and support expanding access to CI as a preventive mental health strategy.