Regular intake of non-opioid analgesics is associated with an increased risk of restless legs syndrome in patients maintained on antidepressants.

OBJECTIVE

To evaluate prevalence and risk factors of restless legs syndrome (RLS) in secondary-care patients maintained on tricyclic and serotonin reuptake inhibiting antidepressants.

METHOD: A total of 243 subjects with affective and anxiety disorders were interviewed for symptoms of RLS before and after at least 6 months of antidepressant pharmacotherapy within a naturalistic study. Logistic regression analysis was applied to adjust for the effects of age, gender, comorbidities, and the most frequent co-medications.

RESULTS

The overall prevalence of RLS was 27%. In the RLS-affected patients, regular use or overuse of non-opioid analgesics frequently combined with caffeine was the major risk factor which significantly correlated with psychiatric and medical comorbidity. In a subsample of 172 patients who had seldom taken analgesics the prevalence of RLS was 9%, which corresponds with its prevalence in the general population.

CONCLUSION

Neither antidepressants nor neuroleptics but non-opioid analgesics appear to be a major risk factor of RLS. Their regular use should be considered in studies of RLS-patients on psychotropic or other drugs. In this sample of secondary-care patients, ICD-10 classified depression or anxiety per se did not appear to be a risk factor of RLS.