Alexithymia in Patients with Somatization Difficulties and Tinnitus-Related Distress: A Systematic Review

Chronic tinnitus, the perception of sound without an external source, can significantly affect individuals' well-being. As an often medically unexplained symptom, chronic tinnitus can present as a "somatoform" or "functional" difficulty. Some evidence has pointed to alexithymia as a transdiagnostically relevant risk factor for both symptom clusters. Using a two-part rapid review-searching within EBSCO, Embase by Ovid, PubMed, Web of Science-we summarize psychological studies regarding alexithymia, i.e., difficulties in recognizing and expressing emotions and (1) somatoform conditions and (2) chronic tinnitus. For the former (inclusion criteria: (1) adult human beings with different kinds of somatization, (2) longitudinal study designs, (3) publication between 2001 and 2021, (4) full-text in English or German) we identified eight studies that revealed significant links between alexithymia and somatoform conditions. Psychotherapy improved alexithymia in most studies. Additionally, alexithymia was associated with broader treatment outcomes such as improvements in pain intensity, gastrointestinal symptoms, and patient-therapist alliance. The 'Risk Of Bias In Non-randomized Studies-of Interventions' tool (ROBINS-I) and 'Revised Cochrane risk-of-bias tool for randomized trials' (RoB 2) were used for risk of bias assessment. Summarizing all available studies on alexithymia and chronic tinnitus, we identified three studies. Inclusion criteria were: (1) adult human beings with chronic tinnitus, (2) publication between 2001 and 2021, (3) full-text in English or German. Risk of bias was assessed by the 'JBI Critical Appraisal Checklist for Analytical Cross Sectional Studies'. The available studies suggested a high rate of alexithymia (65.7%) in patients with chronic tinnitus. Tinnitus-related distress was significantly associated with alexithymia in two studies, one of which, however, found no differences in alexithymia between patients with bothersome versus non-bothersome tinnitus. Conversely, one study reported high levels of alexithymia in patients with low levels of tinnitus-related distress. Overall, alexithymia may be a transdiagnostic psychological indicator of somatization phenomena, which might include some chronic tinnitus presentations. Psychotherapy likely improves alexithymia as well as somatoform symptom presentations.