Treatment of Gilles de la Tourette Syndrome with Cannabis-Based Medicine : Results from a Retrospective Analysis and Online Survey, Leonie M. Milosev et al., 2019

Treatment of Gilles de la Tourette Syndrome with Cannabis-Based Medicine : Results from a Retrospective Analysis and Online Survey


Introduction : Gilles de la Tourette syndrome (GTS) is a neuropsychiatric disorder that is characterized by motor and vocal tics and psychiatric comorbidities, including attention deficit/hyperactivity disorder (ADHD) and obsessive-compulsive behavior/disorder (OCB/OCD). From anecdotal reports and preliminary controlled studies, it is suggested that cannabis-based medicine (CBM) may improve tics and comorbidities in adults with GTS. This study was designed to further investigate efficacy and safety of CBM in GTS and specifically compare effects of different CBM.

Materials and Methods : First, we performed a retrospective data analysis including all those adult patients seen at our clinic, who had used CBM for the treatment of GTS at some time. All these patients were asked to complete an online survey (second study part) to receive more detailed data about treatment with CBM.

Results : From medical records, we identified 98 patients who had used CBM (most often street cannabis followed by nabiximols, dronabinol, medicinal cannabis) for the treatment of GTS: Of the 38 patients who were able to judge, 66% preferred treatment with medicinal cannabis, 18% dronabinol, 11% nabiximols, and 5% street cannabis. Altogether, CBM resulted in a subjective improvement of tics (of about 60% in 85% of treated cases), comorbidities (55% of treated cases, most often OCB/OCD, ADHD, and sleeping disorders), and quality of life (93%). The effects of CBM appear to persist in the long term. Adverse events occurred in half of the patients, but they were rated as tolerable. Dosages of all CBM varied markedly. Patients assessed cannabis (with a preference for tetrahydrocannabinol [THC]-rich strains) as more effective and better tolerated compared with nabiximols and dronabinol. These data were confirmed by results obtained from the online survey (n=40).

Conclusion : From our results, it is further supported that CBM might be effective and safe in the treatment of tics and comorbidities at least in a subgroup of adult patients with GTS. In our sample, patients favored THC-rich cannabis over dronabinol and nabiximols, which might be related to the entourage effect of cannabis. However, several limitations of the study have to be taken into considerations such as the open uncontrolled design and the retrospective data analysis.

Keywords : cannabis; cannabis-based medicine; Gilles de la Tourette syndrome; tics



Gilles de la Tourette syndrome (GTS) is a neuropsychiatric disorder that is characterized by motor and vocal tics. It is often associated with psychiatric comorbidities such as attention deficit/hyperactivity disorder (ADHD), obsessive-compulsive behavior/disorder (OCB/OCD), anxiety, rage attacks, sleeping disorders, and depression.1 Pathophysiologically, most evidence supports a “dopaminergic hypothesis” of GTS manifested by an abnormal interaction between tonic and phasic dopaminergic signaling, resulting in altered modulation of cortico-striato-thalamo-cortical circuitry.2 Accordingly, antipsychotics are the most widely used drugs for the treatment of tics.3,4 However, due to frequently associated adverse events (AEs) and insufficient efficacy, many patients are dissatisfied and, therefore, seek for alternatives, including self-treatment with cannabis.5,6 According to surveys from Germany and Canada, street cannabis leads to a tic reduction of about 60% in more than 80% of patients.5,6 Remarkably, several patients report, in addition, an improvement of psychiatric comorbidities including ADHD, OCD, anxiety, and rage attacks. Most often reported AEs were a feeling of being “high,” decreased concentration, increased anxiety, increased appetite, sedation, irritability, and dry mouth and eyes.5,6

Until today, only two small randomized controlled trials (RCT) have been carried out investigating the efficacy and safety of dronabinol (tetrahydrocannabinol, THC) in GTS.7,8 In both studies, dronabinol was superior to placebo and resulted in a significant tic reduction. The most often reported AEs were tiredness, dry mouth, dizziness, and muzziness. Only recently, single case studies have been published reporting on beneficial effects similar to street cannabis and dronabinol after use of the cannabis extract nabiximols (containing 2.7 mg THC and 2.5 mg cannabidiol [CBD] per puff)9,10 and medicinal cannabis (THC-rich strains),11,12 respectively.

Thus, from available data5–18 it is suggested that cannabis-based medicine (CBM) is effective and well tolerated in the treatment of GTS and improves tics as well as a wide range of comorbidities. It is unclear, however, whether different CBM and routes of intake differ in efficacy and safety. With respect to long-term treatment effects of cannabinoids, so far only limited data obtained from open uncontrolled case studies are available.6,11 This study was designed to increase our knowledge about the effectiveness and safety of CBM in the treatment of GTS, particularly with respect to differences between different CBM.