Methods to detect anxiety in Parkinsons' disease

Anxiety is a common comorbidity of Parkinson's disease (PD), but its classification varies widely, partly due to differences in assessment tools. Participants in a study on anxiety mechanisms in PD were assessed using multiple anxiety instruments. For each, Youden indices were calculated, and prevalence rates and agreement with the Parkinson's Anxiety Scale (PAS) cutoff were examined to establish comparable cut-offs. Associations with health-related quality of life (PDQ-39 scores) were used to assess clinical relevance. 85% of 122 participants reported anxiety in response to a single question, but only 19.7% reported a prior anxiety diagnosis. Using a PAS threshold of 14, 50% were classified as having anxiety. Similar rates were found for the GAD7 (54%) with a cut-off of 4/5 and the MDS-NMS anxiety subdomain (55%) with a cut-off of 13/14, both showing good agreement with the PAS. Lower anxiety rates (22%) were observed with the MDS-UPDRS anxiety item (cut-off 2/3), which had fair agreement with the PAS. Self-reported anxiety and previous diagnoses showed slight agreement with the PAS cut-off. Anxiety classifications using standardised scales correlated with worse PDQ-39 scores, unlike self-reported anxiety. Standardised scales with established cut-offs are preferable to self-report or prior Accepted manuscript diagnoses for identifying anxiety in PD. Aligning cut-offs across different scales may enhance comparability between studies.