Selective impairment of affective theory of mind in restless legs syndrome: a case-control study.

Background: Restless legs syndrome (RLS) is traditionally considered a sensorimotor disorder, but increasing evidence suggests that it may also involve brain systems related to emotional and cognitive functions. In this exploratory study, we investigated whether individuals with RLS show differences in social cognition, particularly in the ability to interpret others' emotional expressions and mental states. Objective: To investigate social cognition in individuals with RLS, particularly affective theory of mind. Methods: We compared 22 individuals with RLS and 22 healthy controls matched for age, sex, and education. Participants completed standardized tasks assessing different aspects of social cognition, including affective theory of mind, which refers to the ability to infer others' emotions. Results: We found that individuals with RLS scored lower on the task assessing affective theory of mind. No significant differences were observed in other social-cognitive measures, although the relatively modest sample size may have limited the detection of subtle differences. The group difference in affective theory of mind remained significant after accounting for depressive symptoms. Conclusion: These preliminary findings suggest that RLS may be associated with alterations in affective theory of mind independent of depressive symptoms. This pattern may reflect involvement of limbic-striatal networks. Larger studies incorporating sleep-related measures are needed to better understand social cognition in RLS.