Association between tinnitus and somatoform disorders.

Pathophysiological mechanisms are often unknown in patients suffering from "idiopathic" tinnitus, and the presence of other unexplained physical symptoms such as those seen in somatoform disorders can be assumed. This study investigates how often tinnitus exists in general medical out-patients with and without somatoform disorders. In an international study initiated by the World Health Organization (WHO), 1275 patients from 12 participating centers located in 11 different countries were examined by means of the WHO Somatoform Disorders Schedule. The overall prevalence of unexplained tinnitus was 11%; however, tinnitus was clearly more frequent among patients with somatization disorder (42%) or hypochondriacal disorder (27%). It was also more frequent than a great number of other symptoms considered to be typical of somatoform disorders. Tinnitus was also related to depression, anxiety, and to symptoms indicating autonomic arousal. Three possible conclusions are discussed: (i) tinnitus may be a somatoform symptom; (ii) the findings may indicate a substantial comorbidity of two different conditions; (iii) tinnitus and somatization may be linked through common mechanisms of arousal and somatic anxiety.