Gender as a Risk Factor for Functional Movement Disorders: The Role of Sexual Abuse.

Background: The prevalence of functional movement disorders is 2 to 3 times higher in women than in men. Trauma and adverse life events are important risk factors for developing functional movement disorders. On a population level, rates of sexual abuse against women are higher when compared with the rates against men.

Objectives: To determine gender differences in rates of sexual abuse in functional movement disorders compared with other neurologic disorders and evaluate if the gender prevalence is influenced by higher rates of sexual abuse against women.

Methods: We performed a case-control series including 199 patients with functional movement disorders (149 women) and 95 controls (60 women). We employed chi-squared test to assess gender and sexual abuse associations and Bayes formula to condition on sexual abuse.

Results: Our analysis showed an association between sexual abuse and functional movement disorders in women (odds ratio, 4.821; 95% confidence interval, 2.089-12.070;  < 0.0001), but not men. Bayesian analysis found the functional movement disorder prevalence ratio between women and men conditional on sexual abuse to be 4.87 times the unconditioned ratio.

Conclusions: There is a statistically significant association between sexual abuse and functional movement disorders in women and a greater likelihood that women who are sexually abused will develop functional movement disorders than men who are sexually abused. Our findings suggest that the increased prevalence of functional movement disorders in women is associated, at least in part, with sexual abuse and its sequelae; however, further research is needed to explore the role of other traumatic and nontraumatic factors.