Medical use of cannabis: Applications to Tourette syndrome

According to the guidelines of the European Society for the Study of Tourette Syndrome (ESSTS) and the American Academy of Neurology (AAN), behavioral therapy and pharmacotherapy with antipsychotics are recommended as first-line treatments for tics in patients with Tourette syndrome (TS). However, almost 30% of patients are considered to be treatment-refractory. Thus, a large number of experimental therapies are being applied; among them is cannabis-based medicine (CBM). From surveys and open uncontrolled studies, it is well known that cannabis flowers and other cannabinoids such as tetrahydrocannabinol (THC) and nabiximols are used by a large number of patients reporting not only a tic reduction, but also an improvement of a wide spectrum of psychiatric comorbidities. From two small randomized controlled trials (RCTs), it is suggested that THC is superior to placebo in the reduction of tics. Currently, we are awaiting the results of the first largest RCT in TS using nabiximols.