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.