Unmasking the gender bias in Tourette syndrome diagnosis

Tourette syndrome is currently diagnosed about three times more frequently in males than in females. A new study finds that female individuals are less likely to be diagnosed with the syndrome, take longer to receive a diagnosis and are older when they are diagnosed than male individuals. The study is published in the January 15, 2025, online issue of Neurology^®, the medical journal of the American Academy of Neurology.

Tourette syndrome is a neurodevelopmental disorder defined by tics, which are sudden, uncontrollable or partially controllable, repetitive movements and sounds that are typically prompted by an irresistible urge to produce them. The study also looked at persistent motor or vocal tic disorder, defined as either vocal or movement tics, but not both. Tics must last for at least a year for either disorder to be diagnosed.

"These results suggest that health care professionals and parents should be screening female individuals with tics and seeking care for them to give them a better chance of managing tics over time," said study author Marisela Elizabeth Dy-Hollins, MD, MSCR, of Massachusetts General Hospital in Boston and a member of the American Academy of Neurology.

Treatment options include education, behavioral therapies, medication and watchful waiting, as tics often improve with time."

 Marisela Elizabeth Dy-Hollins, MD, MSCR, Massachusetts General Hospital in Boston 

For the study, researchers analyzed a dataset of people recruited for genetics research with tic disorders and their family members. From the dataset, they identified 2,109 people with Tourette syndrome and 294 people with persistent motor or vocal tic disorder. The participants were those with tic disorders as well as parents and siblings who were found to have a tic disorder at the time of the screening.

A total of 61% of the female participants had received a diagnosis of Tourette syndrome before the study, compared to 77% of male participants. When researchers adjusted for other factors, they found that female participants were 54% less likely to be diagnosed before the study, despite having the condition.

The study found it took a year longer for female participants to be diagnosed with Tourette syndrome than male participants. For female participants, it took an average of three years from when symptoms started to when they were diagnosed, compared to two years for male participants.

Female participants were also diagnosed at an older age than male participants, an average of 13 years old versus 11 years old.

Female participants also were slightly older when tic symptoms started, an average of 6.5 years old versus 6.0 years old. However, for persistent motor or vocal tic disorder, symptoms started earlier in female participants than in male participants, at an average of 7.9 years old versus 8.9 years old.

A limitation of the study is that it mainly involved white participants, so the results may not apply to other groups.

"More research is needed to understand these differences between female and male individuals in these tic disorders, as well as research involving racial and ethnic populations," Dy-Hollins said.

The study was supported by the National Institutes of Health.