The validation of anxiety rating scales in Parkinson's disease

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. Other anxiety disorders occur with a lower prevalence. Anxiety in PD
is associated with increased subjective motor symptoms, more severe gait
problems and dyskinesias, as well as with freezing and on/off fluctuations.
Anxiety symptoms in PD patients have also been shown to have a negative impact
on health related quality of life.
The study of the prevalence, phenomenology and treatment of anxiety syndromes
in PD has been hampered by a lack of validated rating scales. Whereas
validation of depression rating scales has received much attention in PD, a
systematic review of anxiety rating scales commissioned by the Movement
Disorder Society recently showed that none of the commonly used anxiety rating
scales have been properly clinimetrically evaluated. Since clinimetric
properties of ratings scales depend upon the population they are used in, state
of the art research requires that rating scales are validated for the specific
research populations, such as in this case: PD patients. This validation is an
imperative prerequisite for future studies assessing the efficacy of anxiety
treatments in PD. In addition this study will yield information on
theprevalence and symptomatology of anxiety disorders.

The primary objective of this study is to assess the reliability and validity
of the most commonly used anxiety rating scales in PD within one year. In the
event that none of these scales has satisfactory clinimetric properties,
additional exploratory analysis at item level will be performed to identify the
most important items for inclusion in a new anxiety scale, specific to PD,
which then will require further validation.
The secondary objectives are to study the prevalence and phenomenology of
anxiety disorders in PD, including the description of atypical anxiety
syndromes occurring in PD patients, and anxiety states associated with *off*
periods or periods of dyskinesias in patients with response fluctuations.

This is a one year cross-sectional international multi-centre study involving
360 PD patients. Six centers in the United States (2), Europe (3) and Australia
(1) will participate and each include 60 patients.

no risks associated.