Psychiatry Investig.  2021 Mar;18(3):187-195. 10.30773/pi.2020.0295.

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

• Jeong JE
• Jeon S
• Han JS
• Cho EY
• Hong KS
• Park SN
• Kim JJ

• KMID: 2514351
• DOI: http://doi.org/10.30773/pi.2020.0295

Abstract

Objective
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.
Methods
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.
Results
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.
Conclusion
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.

Keyword

Tinnitus, Brain-derived neurotrophic factor, Serotonin plasma membrane transporter proteins, Genetic association studies, Depression