This is a multicentre, randomized, double-blind, placebo controlled, parallel-group, phase IIIb trial.

Patients (≥18 years) with chronic tic disorders and Tourette syndrome will be recruited.

The objective of the trial is to demonstrate that treatment with the cannabis extract nabiximols is superior to placebo in reducing tics and comorbidities in patients with Tourette syndrome and chronic tic disorders.