Medicinal cannabis ‘life-changing’ for Tourette syndrome – study

Results have been published from one of the first robust clinical studies suggesting medicinal cannabis effectively treats the debilitating effects of Tourette syndrome.

The findings of a new clinical trial add to a small, but growing, body of evidence to support the use of medicinal cannabis in Tourette syndrome. 

Tourettes is a neurological disorder, which causes a range of symptoms including vocal and motor tics. Tics are sudden twitches, movements, or sounds that people are unable to stop themselves from doing. In many cases, tics are not harmful to the person’s overall health, but severe Tourette’s can still have a huge impact on their quality of life.

Existing treatment options include behavioural therapies such as Habit Reversal Therapy (HRT) and Comprehensive Behavioural Intervention Therapy (CBIT), as well as a range of psychiatric drugs. 

However, a small number of early scientific studies – alongside a wealth of anecdotal evidence has suggested that cannabis may be an effective treatment, with it prescribed legally for the condition in countries including the UK. 

READ MORE: Watch the incredible effect medical cannabis has on dad’s Tourettes

The first robust clinical study on cannabis and Tourette’s 

On Tourette Awareness Day, Wednesday 7 June, Australian researchers published new findings a from double-blind, crossover trial, in which patients treated with medicinal cannabis showed a statistically and clinically significant reduction in motor and vocal tics in just six weeks.

In total, 22 participants with severe Tourette syndrome, and representative of the broader population in terms of ethnicity, sex, and co-morbidities, were recruited for the study and randomly assigned to two groups. Participants received both medicinal cannabis oil and a placebo over two six-week blocks.

One group was given a daily dose of oil containing a balanced formulation of CBD and THC over a six-week period, followed by a six-week course of placebo, or vice versa. The dose of cannabis oil was gradually increased to a maximum of 20mg.

A ‘significant reduction’ in tics

Researchers looked at the effects of the treatment on tic severity and impairment, as well as secondary measures including anxiety, depression, and obsessive-compulsive symptoms.

The analysis found a significant association between levels of cannabis in the bloodstream and the response to active treatment. Those treated with the cannabis oil showed a significant reduction in tics, as well as a reduction in obsessive-compulsive symptoms and anxiety, without major adverse effects.

There were no changes in cognitive assessments of attention, working memory, and executive functioning between those receiving the treatment and those given the placebo. 

The researchers conclude: “This study adds to a small body of literature suggesting that oral 1:1 THC:CBD is an effective treatment for tics and psychiatric comorbidity associated with severe Tourette syndrome. Although the adverse-effect profile was mild in this relatively short study, further work is necessary to identify the longer-term effects of cannabis use in Tourette syndrome, such as the possible development of tolerance to the anti-tic effect. 

“The magnitude of the tic reduction observed was moderate, on average, and comparable to the effect observed with existing treatments such as antipsychotic agents.”

The University of Sydney’s Lambert Initiative for Cannabinoid Therapeutics co-funded the study with Wesley Research Institute, and assisted with study design and execution, as well as analysing blood levels of cannabinoids among participants. 

The clinical trial was led by neuropsychiatrist Dr Philip Mosley, a research fellow at the Wesley Research Institute and QIMR Berghofer Medical Research Institute.

“This is the first rigorous and methodical trial of medicinal cannabis to be undertaken in a sufficiently large group of people to make definitive conclusions about its effectiveness,” Dr Mosley said.

“It shows that medicinal cannabis can reduce tics by a level that makes a life-changing difference for people with Tourette syndrome and their families.

“In addition, we found that other symptoms associated with Tourette syndrome in our participants also reduced, particularly symptoms of obsessive compulsive disorder and anxiety.”

Dr Mosley added: “Cannabis interacts with specific receptors on nerve cells in the brain that are part of the body’s own ‘endocannabinoid’ system.

“Effectively, stimulation of these receptors tightens a leaky filter that now stops the involuntary movements and vocalisations from getting out and being expressed by our participants.”

Read the full study here 

A ‘life-changing’ treatment

Study participant, Chris Wright, a 35-year-old who has suffered from severe and often painful tics since childhood, said in a press release that the treatment has changed his life.

“My tics were really painful, not to mention embarrassing and made me self-conscious,” Wright commented.

“The oil has reduced my tics by about 50% and I have been able to read a book for the first time in 10 years. Some days I get home from work and realise I haven’t focused on my Tourette syndrome the entire day. It’s changed my life.”

Dr Philip Mosley, left, supervises as Tourette syndrome patient Chris Wright takes
a dose of the medicinal cannabis. Photo: Wesley Research Institute

The growing body of research for cannabis in Tourette’s 

A previous study conducted in Israel demonstrated the effectiveness of medical cannabis in alleviating symptoms and improving the quality of life for patients diagnosed with Tourette syndrome.

To assess the outcomes, researchers used the Yale Global Tic Severity Scale (YGTSS) and Premonitory Urge for Tic Scale (PUTS), which evaluate the severity, frequency, and interference caused by tics.

After a 12-week treatment period, the results revealed an average reduction of 38% in YGTSS-Total scores and a 20% decrease in Premonitory Urge for Tic Scale (PUTS) scores.

The same group of researchers conducted a study which retrospectively examined a cohort of 42 patients. The findings indicated a significant decrease in both the number and intensity of tics, as well as a reduction in premonitory urges, observed in 83% of the patients.

Real-world data published last year, also on patients in Israel, reported significant improvements in quality of life, employment status and a reduction in their intake of prescription medicines with cannabis treatment. 

Over 60% of patients who were also experiencing obsessive-compulsive disorder (OCD) reported an improvement in these symptoms, as did 89% of patients with anxiety.

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