Anxiety rating scales in Parkinson's disease: critique and recommendations.

Anxiety syndromes are common in patients with Parkinson's disease (PD) with up to 30% suffering from panic disorder, and up to 11% from generalized anxiety disorder (GAD). Anxiety is associated with increased subjective motor symptoms, more severe gait problems, dyskinesias, freezing, and on/off fluctuations. Anxiety has a negative impact on health related quality of life and is strongly associated with depressive syndromes. Since a variety of anxiety scales have been used in PD patients, the Movement Disorder Society commissioned a task force to assess the clinimetric properties of these scales in PD. A systematic review was conducted to identify anxiety scales that have either been validated or used in patients with PD. Six anxiety rating scales were identified. These were the Beck anxiety inventory, the hospital anxiety and depression scale, the Zung self-rating anxiety scale and anxiety status inventory, the Spielberger state trait anxiety inventory, and the Hamilton anxiety rating scale. In addition, Item 5 (anxiety) of the neuropsychiatric inventory was included in the review. No scales met the criteria to be "recommended," and all scales were classified as "suggested." Essential clinimetric information is missing for all scales. Because several scales exist and have been used in PD, the task force recommends further studies of these instruments. If these studies show that the clinimetric properties of existing scales are inadequate, development of a new scale to assess anxiety in PD should be considered.