The Mediating Effect of Psychological Distress on the Association between BDNF, 5-HTTLPR, and Tinnitus Severity

• Published in: Psychiatry investigation Vol. 18; no. 3; pp. 187 - 195
• Main Authors: Jeong, Jo-Eun, Jeon, Sekye, Han, Jae Sang, Cho, Eun Young, Hong, Kyung Sue, Park, Shi Nae, Kim, Jung Jin
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Neuropsychiatric Association 01.03.2021; 대한신경정신의학회
• Subjects: Original; 정신과학; Genetic association studies; Serotonin plasma membrane transporter proteins; Depression; Brain-derived neurotrophic factor; Tinnitus
• ISSN: 1738-3684; 1976-3026
• DOI: 10.30773/pi.2020.0295

To investigate the association between genetic polymorphisms of brain-derived neurotrophic factor (BDNF) or serotonin transporter gene-linked polymorphic region (5-HTTLPR) and tinnitus, and the mediating effects of psychological distress on this association. Eighty-six patients experiencing tinnitus and 252 controls were recruited. The Tinnitus Handicap Inventory was used to assess the severity of tinnitus and the Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory-II (BAI-II), and the Korean version of the Brief Encounter Psychosocial Instrument (BEPSI-K) were used to assess psychological distress. We compared the association of BDNF rs6265 (Val66Met) and 5-HTTLPR variants in the two groups. The mediating effects of BDI-II, BAI-II, and BEPSI-K were examined using multiple regression analysis and validated by the Sobel test and bootstrapping. No significant differences were found between the groups regarding BDNF Val66Met and 5-HTTLPR, but the 5-HTTLPR variants trended toward association. Depressive symptoms appeared to act as a mediator on the relationship within the 5-HTTLPR s/s genotype and the severity of tinnitus. Our findings provide a speculative idea on the association between the serotonergic system and tinnitus and suggest that depressive symptoms act as a mediator in tinnitus. Therefore, screening for depressive symptoms in patients with tinnitus is essential and intervention for depressive symptoms may help alleviate the severity of tinnitus.