The Presence of Serotonin in the Vestibular System: Supporting the Use of SSRIs/SNRIs in the Treatment of Vestibular Disorders—A Narrative Review

Background: Serotonin (5-HT) is a neurotransmitter and a hormone that regulates various functions. Serotonin receptors have been studied in animal experiments in the vestibular system, beginning from the inner ear and vestibular nuclei. However, the role of serotonin in the vestibular system and disorders remains to be clarified. Methods: A review of the literature was performed on different databases according to the PRISMA guidelines. Only publications published on humans and in English have been included. A total of 41 articles were included in this review. Results: There are many publications regarding the use of SSRI/SNRI in vestibular disorders. Regarding persistent postural perceptual dizziness (PPPD) and chronic subjective dizziness (CSD) the available evidence supports multimodality treatment incorporating vestibular rehabilitation, serotonergic medications, and cognitive behavior therapy, although most studies have not included a placebo control group. As for vestibular migraine (VM), SNRI and SSRIs were proposed as preventive therapy and demonstrated a reduction in vertigo attacks in patients with Menière’s Disease (MD), especially when symptoms of anxiety disorder were present. Conclusions: Although SSRIs/SNRIs are considered an off-label therapy for vertigo, several studies have assessed their efficacy in vestibular disorders, as indicated in the data published on PPPD, MD, and VM above all. As some studies report that serotonin receptors are also present in the inner ear and vestibular nuclei, it can be postulated that in cases where the natural levels of serotonin are altered, such as in depression and anxiety, the change in serotonin levels may affect vestibular function and play a role in vestibular disorders.