A Double-Blind, Randomized, Controlled Crossover Trial of Cannabis in Adults with Tourette Syndrome

Efficacy of cannabis-based medicine in the treatment of Tourette syndrome: a systematic review and meta-analysis

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by motor and phonic tics. It is a condition that affects between 0.3% and 0.7% of children, and its pathophysiology remains largely elusive. TS is associated with structural and functional alterations in corticostriatal circuits and neurochemical imbalances. Even though TS is currently incurable, there are established treatment options available, including behavioral therapy and neuroleptics. The use of cannabis-based medicine for tic management is an emerging therapeutic strategy, although its efficacy is still under investigation. It is hypothesized to interact with the endogenous cannabinoid system, but further research is required to ascertain its safety and effectiveness in TS.

AIM

In our systematic review and meta-analysis, we aim to assess the effectiveness of cannabis-based medicine in the treatment of TS.

METHODS

We searched PubMed, Cochrane, Scopus, and Web of Sciences until February 2024. We included clinical trials and cohort studies investigating the efficacy of cannabis-based medicine in the treatment of TS. Data extraction focused on baseline characteristics of the included studies and efficacy outcomes, including scores on the Yale Global Tic Severity Scale (YGTSS), Premonitory Urge for Tics Scale (PUTS), and Yale-Brown Obsessive Compulsive Scale (Y-BOCS). We conducted the meta-analysis using Review Manager version 5.4. software. We compared the measurements before and after drug intake using mean difference (MD) and 95% confidence interval (CI).

RESULTS

In total, 357 articles were identified for screening, with nine studies included in the systematic review and 3 in the meta-analysis. These studies involved 401 adult patients with TS treated with cannabis. YGTSS revealed a significant reduction in total scores (MD = -23.71, 95% CI [-43.86 to -3.55], P = 0.02), PUTS revealed a significant decrease in scores (MD = -5.36, 95% CI [-8.46 to -2.27], P = 0.0007), and Y-BOCS revealed no significant difference in score reduction (MD = -6.22, 95% CI [-12.68 to 0.23], P = 0.06).

CONCLUSION

The current study indicates promising and potentially effective outcomes with the use of cannabis-based medicine in mitigating the severity of tics and premonitory urges. However, there is a need for larger, placebo-controlled studies with more representative samples to validate these findings.

Licensed Medical Cannabis Use in Gilles de la Tourette Syndrome: A Retrospective Long-term Follow-Up

Background: Medical cannabis (MC) is widely used in clinical practice to treat Gilles de la Tourette syndrome (GTS). However, legislation, multiple modes of administration, and inconsistent plant preparations have limited trials to assess its benefits and long-term safety. For the past decade, licensed MC has been authorized in Israel for use in resistant GTS. We aimed to describe subjects' satisfaction, consumption habits, and THC dose increment during long-term usage. Materials and Methods: A retrospective longitudinal data collection (up to 9 years) on cannabis use habits and structured questionnaires evaluating disease characteristics and MC influence from GTS subjects being treated in the Movement Disorders Unit of the Tel-Aviv Medical Center, Israel. Results: Twenty-five patients (84% male) participated in the study. The mean duration of MC use was 4.0±2.3 years (range 0.5-10). The majority of patients (96%) consumed MC primarily, but not exclusively, through inhalation methods such as smoking or vaporizing dried inflorescence. A linear increase was observed in mean monthly THC dose (p<0.0001) with an average increase of 0.6-0.7 g/year. MC led to a subjectively reported reduction in tics (75% average reduction) and symptoms associated with common comorbidities of GTS. MC was generally well tolerated, although most participants (88%) reported experiencing side effects. Conclusions: A subset of GTS subjects who use MC long term under clinical observation may subjectively improve control of symptoms. Subject-led dose increase can indicate emerging tolerance. Large randomized controlled and observational long-term trials are required to confirm these observations.

The Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties. Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery. This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies. Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.

Cannabinoids in the Treatment of Selected Mental Illnesses: Practical Approach and Overview of the Literature

Although an increasing number of patients suffering from mental illnesses self-medicate with cannabis, current knowledge about the efficacy and safety of cannabis-based medicine in psychiatry is still extremely limited. So far, no cannabis-based finished product has been approved for the treatment of a mental illness. There is increasing evidence that cannabinoids may improve symptoms in autism spectrum disorder (ASD), Tourette syndrome (TS), anxiety disorders, and post-traumatic stress disorder (PTSD). According to surveys, patients often use cannabinoids to improve mood, sleep, and symptoms of attention deficit/hyperactivity disorder (ADHD). There is evidence suggesting that tetrahydrocannabinol (THC) and THC-containing cannabis extracts, such as nabiximols, can be used as substitutes in patients with cannabis use disorder.Preliminary evidence also suggests an involvement of the endocannabinoid system (ECS) in the pathophysiology of TS, ADHD, and PTSD. Since the ECS is the most important neuromodulatory system in the brain, it possibly induces beneficial effects of cannabinoids by alterations in other neurotransmitter systems. Finally, the ECS is an important stress management system. Thus, cannabinoids may improve symptoms in patients with mental illnesses by reducing stress.Practically, cannabis-based treatment in patients with psychiatric disorders does not differ from other indications. The starting dose of THC-containing products should be low (1-2.5 mg THC/day), and the dose should be up-titrated slowly (by 1-2.5 mg every 3-5 days). The average daily dose is 10-20 mg THC. In contrast, cannabidiol (CBD) is mainly used in high doses>400 mg/day.

The Effect of Nabiximols on Driving Ability in Adults with Chronic Tic Disorders: Results of a Substudy Analysis of the Double-Blind, Randomized, Placebo-Controlled CANNA-TICS Trial

Background: The multicenter, randomized, double-blind, parallel-group, phase IIIb CANNA-TICS (CANNAbinoids in the treatment of TICS) trial showed clear trends for improvement of tics, depression, and quality of life with nabiximols versus placebo in adult patients with Gilles de la Tourette syndrome and other chronic tic disorders. Although in general nabiximols was well tolerated, it is unclear whether treatment using this cannabis extract influences driving skills in patients with chronic tic disorders. Methods: Here we report results of the "Fitness to Drive" substudy of the CANNA-TICS trial. The key endpoint was fitness to drive as a binary criterion with a computerized assessment at baseline and after 9 weeks of stable treatment (week 13) with nabiximols or placebo. A patient was considered unfit to drive according to the German Federal Highway Research Institute guidelines. Results: In the substudy, a total of 64 patients (76.6% men, mean±standard deviation of age: 36.8±13.9) were recruited at two study sites. The number of patients who were fit to drive increased from 24 (55.8%) at baseline to 28 (71.8%) at week 13 among 43 patients treated with nabiximols, and decreased from 14 (66.7%) to 10 (52.6%) among 21 patients who received placebo. The risk difference (nabiximols - placebo) was 0.17 (95% confidence interval=-0.08 to 0.43) in favor of nabiximols. Specifically, only 2 of 24 (8.3%) patients in the nabiximols, but 4 of 14 (28.6%) patients in the placebo group changed for the worse from fit (at baseline) to unfit (at week 13) to drive, whereas 8 of 19 (42.1%) patients in the nabiximols, and only 2 of 7 (28.6%) patients in the placebo group improved from unfit to fit. Conclusion: Treatment with nabiximols does not impair skills relevant to driving in those patients with tic disorders who were fit to drive at baseline and even improved fitness to drive in a subset of patients who were unfit to drive before start of treatment. EudraCT number: 2016-000564-42.

Tourette syndrome research highlights from 2022

This is the ninth yearly article in the Tourette Syndrome Research Highlights series, summarizing selected research reports from 2022 relevant to Tourette syndrome. The authors briefly summarize reports they consider most important or interesting.

Tourette syndrome research highlights from 2022

This is the ninth yearly article in the Tourette Syndrome Research Highlights series, summarizing selected research reports from 2022 relevant to Tourette syndrome. The authors briefly summarize reports they consider most important or interesting.

A systematic review of cannabidiol trials in neurodevelopmental disorders

Cannabis-derived compounds, such as cannabidiol (CBD) and delta-9-trans-tetrahydrocannabinol (THC), are increasingly prescribed for a range of clinical indications. These phyto-cannabinoids have multiple biological targets, including the body's endocannabinoid system. There is growing scientific interest in the use of CBD, a non-intoxicating compound, to ameliorate symptoms associated with neurodevelopmental disorders. However, its suitability as a pharmaceutical intervention has not been reliably established in these clinical populations. This systematic review examines the nine published randomised controlled trials (RCTs) that have probed the safety and efficacy of CBD in individuals diagnosed with attention deficit hyperactivity disorder, autism spectrum disorder, intellectual disability, Tourette Syndrome, and complex motor disorders. Studies were identified systematically through searching four databases: Medline, CINAHL complete, PsycINFO, and EMBASE. Inclusion criteria were randomised controlled trials involving CBD and participants with neurodevelopmental disorders. No publication year or language restrictions were applied. Relevant data were extracted from the identified list of eligible articles. After extraction, data were cross-checked between the authors to ensure consistency. Several trials indicate potential efficacy, although this possibility is currently too inconsistent across RCTs to confidently guide clinical usage. Study characteristics, treatment properties, and outcomes varied greatly across the included trials. The material lack of comparable RCTs leaves CBD's suitability as a pharmacological treatment for neurodevelopmental disorders largely undetermined. A stronger evidence base is urgently required to establish safety and efficacy profiles and guide the ever-expanding clinical uptake of cannabis-derived compounds in neurodevelopmental disorders. Prospero registration number: CRD42021267839.

Medicinal Cannabis for Paediatric Developmental, Behavioural and Mental Health Disorders

Parents of children with developmental, behavioural and mental health disorders are increasingly asking whether medicinal cannabis might be a therapeutic option for their child. This paper presents the current evidence for medicinal cannabis in this population. Preliminary evidence from open-label studies suggests the potential for medicinal cannabis to ameliorate some symptoms in children with autism spectrum disorder. However, only one double-blind placebo-controlled trial has been completed, with inconclusive findings. Synthetic, transdermal cannabidiol gel has demonstrated efficacy for reducing social avoidance in a sub-group of children with Fragile X syndrome. Studies of medicinal cannabis are planned or underway for children and/or adolescents with autism, intellectual disability, Tourette's syndrome, anxiety, psychosis, anorexia nervosa and a number of specific neurodevelopmental syndromes. High quality evidence from double-blind placebo-controlled trials is needed to guide clinical practice.

CANNA-TICS: Efficacy and safety of oral treatment with nabiximols in adults with chronic tic disorders - Results of a prospective, multicenter, randomized, double-blind, placebo controlled, phase IIIb superiority study

Preliminary data suggest that cannabis-based medicines might be a promising new treatment for patients with Tourette syndrome (TS)/chronic tic disorders (CTD) resulting in an improvement of tics, comorbidities, and quality of life. This randomized, multicenter, placebo-controlled, phase IIIb study aimed to examine efficacy and safety of the cannabis extract nabiximols in adults with TS/CTD (n = 97, randomized 2:1 to nabiximols:placebo). The primary efficacy endpoint was defined as a tic reduction of ≥ 25% according to the Total Tic Score of the Yale Global Tic Severity Scale after 13 weeks of treatment. Although a much larger number of patients in the nabiximols compared to the placebo group (14/64 (21·9%) vs. 3/33 (9·1%)) met the responder criterion, superiority of nabiximols could formally not be demonstrated. In secondary analyses, substantial trends for improvements of tics, depression, and quality of life were observed. Additionally exploratory subgroup analyses revealed an improvement of tics in particular in males, patients with more severe tics, and patients with comorbid attention deficit/hyperactivity disorder suggesting that these subgroups may benefit better from treatment with cannabis-based medication. There were no relevant safety issues. Our data further support the role of cannabinoids in the treatment of patients with chronic tic disorders.