You might want to look at the book Phobia Free by Harold Levinson. It doesn't look relevant at first glance but has a lot of stuff about brain chemistry.
Phobia Free: Medical Breakthrough Linking 90% of all Phobias and Panic Attack to a Hidden Physical Problem: Harold N Levinson, Steven Carter: 9780871315397: Amazon.com: Books
I have OCD, and after looking at OCD and Tourette's, I am convinced they are highly related (and certainly correlated), if not actually the same thing. And they seem to be related and correlated with a bunch of other problems.
Levinson approaches it as an inner-ear disturbance, and mentions medications and supplements that help. Some are OTC, others are prescription only.
Anyway, as a place to continue your research, I think I would be a useful step. Good luck!