Does the Association Between Anxiety and Parkinson's Disease Really Exist? A Literature Review

Introduction: Although anxiety is a common psychiatric complication of Parkinson's disease (PD), it has received little attention compared to depression in PD, being still an under-recognized and under-diagnosed condition in clinical practice. Objective: To review general aspects of the association between anxiety and PD concerning prevalence, etiopathogenesis, clinical characteristics, comorbidities, and treatment. Method: The basic and clinical literature on anxiety and PD was reviewed via the Pubmed, Lilacs and Scielo indexing services, using the keywords anxiety, etiology, prevalence, treatment, Parkinson, and Parkinson's disease. Moreover, complementary information was extracted from the reference lists of the articles found in the search. Results: Up to 67% of PD patients present clinically significant anxiety levels. Oscillations in anxious symptoms may be related to the use of anti-Parkinson drugs and motor fluctuations. The association between anxiety in PD and depressive disorders sleep disturbances, and cognitive impairment has also been proposed as a possible explanation for this psychiatric complication. Thus far, few data on the treatment of anxiety disorders in PD are available. Conclusions: More studies investigating aspects such as prevalence, etiopathogenesis, comorbidities, impact on life quality, and treatment are necessary and opportune in order to facilitate the recognition and diagnosis of anxiety disorders in PD.