A recent study published in the Proceedings of the National Academy of Sciences indicates that serotonin, a neurotransmitter commonly used to alleviate symptoms of depression and anxiety, may exacerbate the uncomfortable condition known as tinnitus. Tinnitus is characterized by a persistent ringing or buzzing in the ears, affecting an estimated 14% of the global population, with many individuals experiencing significant distress.
Researchers from Oregon Health & Science University and Anhui University in China explored this phenomenon using a mouse model, discovering that elevated levels of serotonin in the brain were linked to increased behavioral symptoms of tinnitus. The co-lead author of the study, Laurence Trussell, Ph.D., Professor of Otolaryngology at OHSU School of Medicine and scientist at both the OHSU Vollum Institute and the Oregon Hearing Research Center, emphasized the relevance of these findings for the millions affected by tinnitus worldwide.
“Individuals suffering from tinnitus should collaborate closely with their prescribing physician to establish a medication regimen that balances the alleviation of psychiatric symptoms like depression and anxiety with the minimization of tinnitus experiences. This study highlights the necessity for healthcare providers to acknowledge and validate patient reports regarding medication-induced tinnitus worsening,”
Laurence Trussell, Ph.D.
This research is particularly pertinent as it pertains to a common class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs), which elevate serotonin levels in the brain to relieve moderate to severe depression and anxiety symptoms. Co-author Zheng-Quan Tang, Ph.D., from Anhui University, noted that while there were suggestions in previous studies regarding serotonin’s involvement in tinnitus, their research was able to pinpoint a specific neural circuit in the brain that directly connects to the auditory system and induces tinnitus-like effects. The researchers reported significant relief when this circuit was deactivated.
“This gives us a much clearer understanding of the underlying neural dynamics involved,” said Tang, underscoring new potential treatment avenues.
Advancements in Understanding Tinnitus
The recent investigation marked substantial progress compared to earlier studies conducted in 2017. Utilizing optogenetic techniques, researchers directed light precisely into the brain to trigger the electrical activity of neurons that produce serotonin, subsequently assessing the behavioral responses of the mice using a modified acoustic startle response test.
“When we stimulated these serotonergic neurons, we observed a heightened activity in the brain’s auditory region,” noted Trussell. “We also found that the mice exhibited behaviors indicating they perceived tinnitus, mimicking the human experience.”
These findings resonate with many individuals who have reported worsening of their tinnitus symptoms when using serotonin-boosting medications like SSRIs, Trussell stated. “Our study suggests that there exists a delicate balance; it may be feasible to develop medications that target specific cells or brain regions to control serotonin increases in certain areas while conserving its benefits in others. This could potentially allow us to separate the therapeutic effects of antidepressants from their adverse impacts on hearing,” he concluded.
Source:
Oregon Health & Science University
Reference:
Yu, M.-T., et al. (2026). A discrete serotonergic circuit involved in the manifestation of tinnitus behavior. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2509692123. https://www.pnas.org/doi/10.1073/pnas.2509692123
