Frequency of social phobia and psychometric properties of the Liebowitz social anxiety scale in Parkinson's disease

There are few studies about social anxiety disorder in Parkinson's disease (PD). The objective of this study was to assess its frequency and to explore the psychometric properties of the Liebowitz social anxiety scale (LSAS) in PD. Ninety patients with PD underwent neurologic and psychiatric examination. Psychiatric examination was composed by a structured clinical interview (MINI-Plus) followed by the application of the LSAS, the Hamilton depression rating scale (Ham-D), and the Hamilton anxiety rating scale (Ham-A). Neurologic examination included the MMSE, the UPDRS, the Hoehn-Yahr Scale, and the Schwab-England scale of activities of daily living. Social phobia was diagnosed in 50% of PD patients. The disorder was not associated with any sociodemographic or neurological feature, but was associated to major depression (P = 0.023), generalized anxiety disorder (P = 0.023), and obsessive-compulsive disorder (P = 0.013). The score of LSAS correlated positively with the scores of Ham-D and Ham-A (P < 0.001 for both). A ROC curve analysis of the LSAS suggested that a cutoff score in 41/42 provided the best balance between sensitivity and specificity. This disorder seems to be more common and not just restricted to performance as previously thought.