Muller‐Vahl 2003/1.

Methods	Single centre, double blind, placebo controlled, parallel group 6 week study
Participants	24 adult patients 19 male 5 female. Mean age 33
Interventions	THC titrated to target dose10mg/day
Outcomes	Tic severity using Tourette syndrome Clinical Global Impressions scale; the Shapiro Tourette‐syndrome Severity Scale; the Yale Global Tic Severity Scale; a video protocol for assessment of tic intensity and frequency; and a patient self rating scale the Tourette Syndrome Symptom List.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate