Application of depression rating scales in patients with Parkinson's disease with and without co-Occurring anxiety.

Background: In patients with Parkinson's disease (PD), depressive symptom rating scales facilitate identification of depressive disorders, which are common and disabling. Anxiety disturbances in PD, which lack valid assessment scales, frequently co-occur with PD-depression, are under-recognized, and require different interventions than depressive disorders. Whether high anxiety rates in PD confound depression scale performance or if any depression scales also predict anxiety disturbances is not known.