Here is some reading and background information concerning Tourettes and medical marijuana. Please note some of these may not be the latest information but are included to offer a wide range of sources and opinions, they do not constitute medical advice, and in almost every case more research is needed before there is certainty.
Marijuana & Tourette: Tourette Canada
Can medicinal cannabis treat the tics in Tourette syndrome?
Treatment of Tourette syndrome with cannabinoids.
How medical cannabis can diminish Tourette’s motor and vocal tics