The neurological disorder Tourette’s syndrome (TS, if you like) is the most well known of a family of tick disorders that are all characterized by involuntary repetitive movements and vocalizations. Tourette’s is infamous for spectacular and uncontrollable fits of swearing. But coprolalia is present in only about 10 percent of cases. (I once heard a woman speak whose verbal tick was to say “hedgehog,” very, very frequently. As endearing as it was to us listeners, it was no easier on her than stammering shit-shit-shit.) Tics also commonly include sniffing, grunting, throat clearing, blinking, grimacing, shrugging, and general ants-in-your-pantsing.
Like autism, Tourette’s usually emerges in childhood and it heavily favors boys. It is often accompanied by a ADHD, obsessive compulsive disorder, and a host of behavior, learning, and mood disorders.
The idea that cannabis might be an effective treatment for Tourette’s was first suggested back in 1988. It was in a case study of three patients whose tics would subside after a joint or two. There’s still not a whole lot of research, but a good chunk of what has been done is the work of Kirsten Müller-Vahl of the Hannover Medical School.
Her latest paper on the subject (from 2013) is a very accessible overview of the research to date, in which she concludes that the data—although admittedly slight—“consistently provide evidence for beneficial effects of cannabinoids in the treatment of tics in patients with TS.” She also finds “weak evidence” that cannabis may also improve behavior problems associated with the illness, such as obsessive compulsive behavior, short attention, and impulsivity.
Despite Dr. Müller-Vahl’s optimistic prognosis, the clinical proof is simply not there yet. A 2009 paper from a British research group, which was the most comprehensive review of its time, found only two studies that met its criteria. It concluded—unsurprisingly—that “there was not enough evidence” to support the use of cannabinoids in treating tics and obsessive compulsive behaviour in people with Tourette’s syndrome.” [That’s a legitimate British “-our” back there, and not my being a poseur slipping out again.]
That unenthusiastic position was seconded by the American Medical Association, in its own review of medical-marijuana literature from 2015. Because of small sample size, it concluded that there was only “low-quality evidence” for the efficacy of cannabis in treating Tourette’s.
Another review from that year, however, used looser criteria, admitting surveys and case reports, and found that tics caused by Tourette’s “did respond to cannabis preparations,” and concluded that there is a “promising role” for the drug in Tourette’s therapy.