Assessing Sex Differences in Individuals with Tourette Syndrome and Persistent Motor or Vocal Tic Disorder
Marisela Dy-Hollins1, Lori Chibnik2, Lisa Osiecki1, Nutan Sharma1, Carol Mathews4, Jeremiah Scharf3
1Massachusetts General Hospital, 2Neurology and Epidemiology, 3Neurology, Massachusetts General Hospital, 4Department of Psychiatry and Center for OCD, Anxiety, and Related Disorders, University of Florida
Objective:
To examine sex differences in Tourette Syndrome (TS) and Persistent Motor or Vocal Tic Disorder (PMVT) individuals.
Background:

TS and PMVT are more prevalent in males compared to females. Females with TS may have a delayed diagnosis and more complex tics than males. Obsessive-compulsive disorder (OCD) is more prevalent in females; attention-deficit hyperactivity disorder (ADHD) is more prevalent in males. This study analyzes sex differences in outcomes among TS and PMVT.

Design/Methods:

Data from 2405 individuals (N=2109 TS; N=168 PMVT) from the Tourette Association of America International Consortium for Genetics were analyzed to explore the relationship between sex and TS or PMVT outcomes: 1) age at tic onset; 2) time-to-diagnosis; 3) tic severity; and 4) comorbidity rates. Regression models adjusted for age, sex, and family relationships.

Results:

Females with TS (25.5% of the sample) compared to males had a later age of symptom onset (6.5±2.8 vs. 6.0±2.7; p=0.001), and a longer time-to-diagnosis [3 (1,7) vs. 2 (1,5), p=0.01]. OCD was more prevalent in females (55% vs. 48.7%; p=0.01) as well as ADHD (61.1% vs. 55.7%; p<0.001).  After adjusting for sex, age, and family relationships, females had lower odds of ADHD [0.6 (0.5, 0.7)].

Females with PMVT (42.9% of the sample) compared to males had an earlier age of symptom onset (7.9±3.3 vs. 8.9±3.7; p=0.05). OCD was more prevalent in females (41.9% vs. 22.2%; p<0.001), but not ADHD. Results were significant after adjusting for sex, age, and family relationships.

Conclusions:
Females with TS may be clinically different than males with TS. ADHD appeared more prevalent in females with TS in univariate analyses, but less prevalent in regression models. In contrast, females with PMVT appear similar compared to males with PMVT.  Age of symptom onset is later in females with TS, but earlier in females with PMVT. Meta-analyses may help to better understand these findings.
10.1212/WNL.0000000000202217