Mild motor signs and depression: more than just medication side effects?

The relationship between major depressive disorder (MDD) and mild motor signs (MMS) remains to be elucidated. The present study aims to assess the association between neurological symptoms and medications and treatment response. Neurological signs in 790 patients with MDD were correlated with treatment outcome. Three hundred ten (39.2%) were responders and 480 (60.8%) were non-responders. 342 (43.3%) presented neurological signs. In the whole sample negative associations between dystonia and rigidity and various medications was observed. Non-response was associated with dystonia, rigidity, and hypokinesia independent from age and medications. This study highlighted an association between MMS and specific medications. Moreover, MMS were associated with non-response to treatment, regardless of medication use. This may suggest that a subgroup of patients with MDD may respond less to therapy because of an underlying still undetected neurological disorder.