Tourette's Syndrome, or TS is a neuropsychiatric disorder characterized by involuntary tics. While often portrayed in the media for comedic effect, it's a serious disease, and patients who suffer from the more debilitating forms can cause serious injury to themselves because of the tics and spasms. Estimates say that there are about 100,000 people with Tourette's Syndrome in the United States alone. At present, there is no known cure, but patients say their symptoms lessen as they age.
Beginning with a casual German study in 1997, there have been several research products that have demonstrated that TS patients may see a decrease in their tics and other related behaviors, such as obsessive-compulsive disorder, when using THC, the "active ingredient" in cannabis. None of the studies showed any impairment of cognitive function.
A more recent, more comprehensive study took place in 2003. In that study, Tourette's Syndrome patients were given either THC or placebo for six weeks, and asked to track their daily tics. Patients taking THC showed a significant decrease in tics, with no adverse effects, or negative effects on verbal memory, recall, or learning abilities. In a paper published in the Journal of Clinical Psychiatry, the researchers' conclusion was that "Therapy with delta-9 THC should be tried…" at least for adult patients.
Today, the use of medical marijuana to treat Tourette's is still not officially sanctioned, even in the states where cannabis is authorized to treat other diseases. In Colorado, it was recently rejected as an authorized disease for medical marijuana certification. Nevertheless, when the traditional treatments for TS fail to work, or the only available medications come with risky side effects (at least one can cause heart problems), both clinical and anecdotal evidence support the use of cannabis as a viable option.