Systematic review on the evidences of an association between tinnitus and depression

Tinnitus has been associated with several psychiatric disorders, however there are still several questions regarding such association. Objective: To assess the scientific evidence on the associations between symptoms of depression, depression, and tinnitus. Method: A systematic review was performed using PubMed, Lilacs, and SciELO scientific databases. This review included studies published in Portuguese, Spanish, or English correlating tinnitus with depression; letters to the editor and case reports were excluded. Results: A total of 64 studies were identified, of which only 20 met the inclusion criteria and only 2 were case-control clinical trials. The majority of the studies (n = 18) found that depression is associated with tinnitus, either as a predisposition - resulting in poor adaptation to tinnitus or as a consequence of severe disease. Conclusion: An overall assessment of all of the selected studies suggests at least 3 possible associations between depression and tinnitus: depression affecting tinnitus, tinnitus predisposing individuals to depression, and tinnitus appearing as a comorbidity in patients with depression. There is a high prevalence of depressive symptoms in individuals with tinnitus, but the mechanisms by which depression and tinnitus mutually interact, are not fully understood.