And the answer is: likely?:
(Suggest you do not read that if prone to anxiety.)
Moreover … it looks like Serotonin has a role in regulating the endolymph!:
However, this might explain why anxiety and/or issues with serotonin regulation might cause issues with dizziness and balance. (hence the experience of the above patient?).
Given dizziness and balance issues then cause anxiety … well … you can fill in the next bit …