It has been reported that restless legs syndrome (RLS) might be associated with multiple psychosomatic symptoms. We aimed to identify which psychosomatic symptom is the most related in RLS patients compared to healthy controls. We also attempted to determine the relation between psychosomatic comorbidity and RLS severity regardless of sleep-related symptoms.

One hundred two newly diagnosed patients with RLS and 37 healthy control subjects participated in the present study. The RLS patients were categorized as mild and severe based on the International RLS Study Group rating scale. Data on demographics were collected. All participants completed the Pittsburgh Sleep Quality Index, Athens Insomnia Scale, and Epworth Sleepiness Scale as sleep-related questionnaires. All participants completed the Symptom Checklist-90-Revision (SCL-90-R).

RLS patients were found to have pervasive comorbid psychosomatic symptoms. Somatization was found to be the most significant contributing factor (OR 1.145, 95 % CI 1.061–1.234, p < 0.001) for psychosomatic comorbidity in RLS. Severe RLS patients were found to have poorer sleep quality than mild RLS patients. Furthermore, severe RLS patients had higher scores for most psychosomatic symptom domains in SCL-90-R. Anxiety was found to be the most independent contributing factor for psychosomatic comorbidity according to RLS severity (OR 1.145, 95 % CI 1.043–1.257, p = 0.005).

Our study demonstrates that comorbid psychosomatic distress is considerable in patients with RLS. Furthermore, most psychosomatic comorbidity is increased with the RLS severity in association with poorer sleep quality.