Clinical Programs

Marijuana studied as treatment for tics of Tourette syndrome

NEW HAVEN — Marijuana is being studied as a treatment for Tourette syndrome’s involuntary movements and vocalizations.

While the Board of Physicians for the state Department of Consumer Protection’s medical marijuana program rejected Tourette syndrome as an approved condition, researchers are studying the properties in cannabis that appear to help relieve the tics that come with the disorder, according to Dr. Michael Bloch, an associate professor at the Yale Child Study Center and assistant director of the center’s Tic Disorder/Obsessive Compulsive Disorder Specialty Clinic.

Tourette syndrome typically appears in children between 4 and 6 years old, two-thirds of them boys. But “about one-half to two-thirds of kids with Tourette’s get better in adolescence and we really don’t know why,” Bloch said. “You have involuntary movements or vocalizations that typically change in character over time.”

Fortunately, symptoms decrease as children get older. “Most times, since the tics are going to get better on their own … often the major treatment intervention would be just trying to minimize the impairment,” Bloch said, addressing problems the tics cause in school, at home or with friends.

Bullying is a problem for children with Tourette. “Oftentimes these kids get bullied or made fun of because the other kids don’t understand,” Bloch said. A child with an eye-rolling tic might be misinterpreted as making fun of a classmate. The Tourette Association of America has local youth ambassadors to help educate students about the disorder.

Anecdotal evidence for cannabis

He said that while about 80 percent of Tourette patients who smoke marijuana say it reduces the severity of their tics, more research is needed. The need for double-blind controlled studies was the reason the Board of Physicians did not allow those with Tourette to purchase medical marijuana, according to Dr. Cyril Deepak D’Souza, a member of the board who researched the issue in 2016 and found that no randomized clinical trials had been conducted on Tourette, Alzheimer’s disease or post-traumatic stress disorder.

According to Bloch, “Smoking it may be associated with more long-term potential side effects than taking it in other forms. … The evidence is premature to say that smoking marijuana helps tics.”

However, the chemical components of cannabis have been shown in clinical trials to reduce the severity of Tourette’s symptoms. They have resulted in one medication, dronabinol, marketed as Marinol or Syndros, which is a manufactured form of tetrahydrocannabinol, or THC, the component of marijuana that gives users a high. It’s been approved by the U.S. Food and Drug Administration for adults to reduce nausea caused by chemotherapy, Bloch said.

“If you gave patients with tics dronabinol, they have significant reductions in their tics compared to placebo,” Bloch said. In one study under way at Yale, patients are given dronabinol along with palmitoylethanolamide, or PEA, which is an endocannabinoid, a cannabinoid produced in the body. THC is an endocannabinoid as well as being an active component of marijuana.

“It’s just looking at whether you can add this endocannabinoid PA on top of the dronabinol, and the thought is it’s going to reduce the side effects of the THC and potentially make it work better,” Bloch said.

“An absolute miracle”

Jackie, a 30-year-old woman who asked that her last name not be used, took part in that study for 36 weeks. “My condition really started when I was 18, which is very abnormal and it started mostly with eye-blinking and throat-clearing,” she said. Her symptoms only worsened in her 20s, with “forceful neck movements,” which caused nerve damage, and violent wrist movements.

“I tried multiple medications … and different kinds of therapy … and nothing worked,” Jackie said. She underwent habit-reversal therapy, in which she would cover her eyes when she felt a blinking tic coming on. She even tried medications that are designed for other diseases in an attempt to find relief. Her tics occurred as often as twice a minute.

“It affected me majorly socially. I didn’t go to college because of it and I was put into a private high school my last two years … because I couldn’t handle a classroom.” She was unable to go to college and missed her brother’s and sister’s college graduations.

Fortunately, the dronabinol-plus-PEA regimen worked for her. Even after completing the 36 weeks, she is now “90 percent better, which is an absolute miracle. … As of nine months ago, I had no hope at all,” she said.

While marijuana and its chemical components are being researched, “Right now there are fairly few treatments for Tourette,” Bloch said. “The most effective treatments we have for tics are anti-psychotic medications,” but they come with side effects such as an increased risk of diabetes.

Bloch said that those with Tourette can feel a tic coming on and can suppress it, at least for a while, “but only at the expense of mounting discomfort.” He said the feeling can be compared to suppressing a sneeze or a need to urinate. “You can keep holding it, but it keeps feeling more and more uncomfortable,” he said.

The image of a Tourette sufferer shouting curse words is only partially accurate, Bloch said. Known as coprolalia, it afflicts about 10 percent of adults with Tourette and “a significant minority” of children, Bloch said. “I see a few of those cases, but they’re pretty unusual,” he said. “Most people with Tourette’s have much more mild cases than that.”

By the time they reach adulthood, “about a third don’t have any noticeable symptoms,” he said. With another third, “you might be able to sit with them for an hour or so and not notice” that they have the disorder. For some, stress or fatigue can bring on more tics.

About half of those with Tourette also have attention deficit hyperactivity disorder and a third have obsessive compulsive disorder. “Typically, the ADHD starts before the tics and the OCD starts around the time the tics are at their worst,” at 10 to 12 years old, Bloch said.

Contact Ed Stannard at or 203-680-9382.