Association between hospital-diagnosed tinnitus and suicide: A Nationwide Danish longitudinal study

Objectives: Tinnitus is a source of significant distress among some people. Associations have been suggested between tinnitus and mental disorders, and with suicidal thoughts and attempts. However, whether this extends to suicide in the general population remains uncertain. Methods: This is a retrospective cohort study including all individuals aged 15 years or older, using Danish nationwide, longitudinal, population-based register data from 1 January 1990 through 31 December 2021. The main outcome was death by suicide. Poisson regression models were used to estimate adjusted incidence rate ratios (IRR) with the 95% confidence intervals (CI). Results: Among 7,438,007 individuals (49.8% males) observed over 144,050,344 person-years, 85,677 (57.7% males) were diagnosed with tinnitus. In all, 23,824 suicide deaths were identified, of which 225 had tinnitus. Suicide rates were 24.2 and 16.5 per 100,000 person-years for those with and without tinnitus, respectively, giving an adjusted IRR of 1.4 (95% CI 1.2-1.6). Suicide rates were adjusted for demographic characteristics, concomitant hearing loss, and co-existing mental disorders before tinnitus. Increased suicide rates were linked to a higher number of hospital contacts and to recent hospital contacts, suggesting dose-response and temporal associations. Conclusions: The findings reveal an association between tinnitus and suicide, particularly among individuals with co-existing mental disorders. Dose-response and temporal associations were found between tinnitus and suicide. Concurrent hearing loss had no influence on the tinnitus-suicide association. Attention towards patients experiencing tinnitus related distress is warranted, especially those with pre-existing mental disorders.