Clinical Markers of Anxiety Subtypes in Parkinson Disease.

OBJECTIVE: The aim of this work was to investigate marker profiles for proposed anxiety subtypes in Parkinson disease (PD). METHODS: We used the persistent anxiety, episodic anxiety, and avoidance behavior subscales of the Parkinson Anxiety Scale as dependent variables in multivariable linear regression analyses using a cross-sectional data set of 311 patients with PD. Independent variables consisted of a range of demographic, psychiatric, and disease-specific markers. RESULTS: In the most parsimonious model of persistent anxiety, higher Hamilton Depression Rating Scale scores, a history of anxiety, fewer years of education, lower Mini-Mental State Examination scores, lower Lawton Instrumental Activities of Daily Living scores, female sex, and complications of therapy (higher Unified Parkinson Disease Rating Scale part IV scores) were all associated with more severe persistent anxiety. Markers associated with more severe episodic anxiety included PD-specific disturbances of activities of daily living, complications of therapy, higher Hamilton Depression Rating Scale scores, female sex, and a history of anxiety. Finally, higher Hamilton Depression Rating Scale scores, a history of anxiety, complications of therapy, and longer disease duration were associated with avoidance behavior. After excluding clinically depressed patients with PD, disease severity and longer disease duration were significantly associated with episodic anxiety, but not with persistent anxiety. CONCLUSION: Persistent anxiety is mainly influenced by nonspecific markers, while episodic anxiety seems to be more PD-specific compared to persistent anxiety and may be more situational or contextual. These results provide support for possible distinct underlying constructs for anxiety subtypes in PD.

Designing a new scale to measure anxiety symptoms in Parkinson's disease: item selection based on canonical correlation analysis.

BACKGROUND AND PURPOSE: The lack of appropriate measures has hindered the research on anxiety syndromes in Parkinson's disease (PD). The objective of the present cross-sectional, international study was to identify shared elements and grouping of components from anxiety scales as a basis for designing a new scale for use in PD. METHODS: For this purpose, 342 consecutive PD patients were assessed by means of the Mini International Neuropsychiatric Inventory (depression and anxiety sections), the Clinical Global Impression of severity of the anxiety symptoms, the Hamilton Anxiety Rating Scale (HARS), the Neuropsychiatric Inventory (section E), the Beck Anxiety Inventory (BAI) and the Anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A). RESULTS: As the HADS-A showed a weak correlation with the HARS and BAI, it was not considered for more analyses. HARS and BAI exploratory factor analysis identified nine factors (62% of the variance), with only two of them combining items from both scales. Therefore, a canonical correlation model (a method to identify relations between components of two groups of variables) was built and it showed four factors grouping items from both scales: the first factor corresponded to 'generalized anxiety'; the second factor included muscular, sensory and autonomic 'non-specific somatic symptoms'; the third factor was dominated by 'respiratory symptoms'; and the fourth factor included 'cardiovascular symptoms'. CONCLUSIONS: BAI is heavily focused on panic symptoms, whilst HARS is more focused towards generalized anxiety symptoms. The new scale should include additional components in order to assess both episodic and persistent anxiety as well as items for evaluation of avoidance behaviour.