The Relationship Between Social Anxiety Disorder and Motor Symptoms of Parkinson Disease: A Pilot Study

In patients with Parkinson disease (PD), motor symptoms coexist with several nonmotor neuropsychiatric symptoms. Various anxiety subtypes (generalized anxiety disorder, panic disorder, and social anxiety disorder [SAD]) are more prevalent in patients with PD than in the general population.

We estimated the prevalence of SAD in early patients with PD and the relationship between severity of SAD and PD symptoms.

The Liebowitz Social Anxiety Scale (LSAS) and Unified Parkinson's Disease Rating Scale (UPDRS) III, which assess function impairment, were used to grade symptom severity among 41 patients with early PD. Ratings were compared and analyzed in relation to UPDRS subdivisions.

UPDRS III and LSAS scores were not significantly correlated (r = 0.23, P = 0.14), but LSAS and UPDRS I, which evaluate nonanxiety psychiatric symptoms, were significantly correlated (r = 0.44; P = 0.004) and were stronger in the group not treated for PD (r = 0.82) but were in the group treated for PD (r = 0.28), although this difference did not reach statistical significance (P = 0.07 using the Fisher r-to-z transformation). LSAS also correlated with total UPDRS and UPDRS II (P ≤ 0.04).

Results suggest that SAD symptoms in patients with PD correlate with PD symptoms as evaluated by the total UPDRS and UPDRS I and II. In our pilot study, this correlation was higher in levodopa-untreated patients with PD but was not statistically significant. Because the UPDRS III and LSAS were not statistically significantly correlated, a direct motor correlation with SAD symptoms cannot be suggested. Further investigation is needed to clarify the relationship of SAD in patients with PD and potential treatment options.