Background: Symptoms of anxiety and depression in patients with restless legs syndrome (RLS) have been observed. However, it is unclear whether rates of threshold depression and anxiety disorders according to DSM-IV criteria in such patients are also elevated. Methods: 238 RLS patients were assessed with a standardized diagnostic interview (Munich- Composite International Diagnostic Interview for DSM-IV) validated for subjects aged 18–65 years. Rates of anxiety and depressive disorders were compared between 130 RLS patients within this age range and 2265 community respondents from a nationally representative sample with somatic morbidity of other types. Results: RLS patients revealed an increased risk of having 12-month anxiety and depressive disorders with particularly strong associations with panic disorder (OR=4.7; 95% CI=2.1–10.1), generalized anxiety disorder (OR=3.5; 95% CI= 1.7–7.1), and major depression (OR=2.6; 95% CI=1.5–4.4). In addition, lifetime rates of panic disorder and most depressive disorders as well as comorbid depression and anxiety disorders were considerably increased among RLS patients compared with controls. Conclusions: The results suggest that RLS patients are at increased risk of having specific anxiety and depressive disorders. Causal attributions of patients suggest that a considerable proportion of the excess morbidity for depression and panic disorder might be due to RLS symptomatology.