Sept. 30 (HealthDay News) -- Some studies have suggested that strep throat may cause or trigger obsessive-compulsive disorder and Tourette syndrome, but extensive new research has found no evidence of a link.

"Streptococcal infection has previously also been linked to other, much rarer neuropsychiatric disorders," Dr. Anette Schrag of the University College London and an author of the study said in a news release from the American Academy of Neurology. "These results do not confirm other, smaller studies done in the U.S. which found an association between strep infection and these brain disorders."

The study involved 255 residents of the United Kingdom, 2 to 25 years old, including 129 who had obsessive-compulsive disorder (OCD) and 126 with Tourette syndrome or tics, a symptom of that condition. The researchers compared incidents of strep throat infection in the 255 participants with that of 4,519 people who had neither condition.

Of those with OCD, about 15 percent had possible exposure to strep throat in the two years before they were diagnosed with their disorder; that was the case for 10 percent of those with Tourette syndrome. The rates were similar to those in the group without the conditions, the study found. The researchers found similar rates of strep infection five years before diagnosis as well.

This suggests, according to the researchers, that strep throat does not have a connection to either disorder.

The findings are published online Sept. 30 in Neurology.

SOURCE: American Academy of Neurology, news release, Sept. 30, 2009