Anxiety disorders in Parkinson's disease

Clinically significant anxiety syndromes are a common problem in PD, with prevalence rates of up to 40% of patients with Parkinson's disease (PD). Although limited attention has been paid to PD-related anxiety disorders, they contribute substantially to morbidity and caregiver burden. In some patients, the anxiety syndrome is a prevailing problem, over and above the impairment related to motor dysfunction. There is also evidence that anxiety disorders in PD are fundamentally related to underlying neurodegenerative processes. While anxiety syndromes occur in isolation, there is also overlap among anxiety symptoms and signs, PD-related depressive syndromes, PD motor phenomena, and effects of antiparkinsonian medications. Together, these factors can contribute to the misattribution of pathological anxiety as a normal psychological reaction to motor-related disability, and, hence, reduced recognition and treatment of a discrete anxiety syndrome. The primary aims of this article are to review the clinical features of the different anxiety syndromes in PD, describe the potential interplay between motor, cognitive, and affective abnormalities, and discuss the proposed mechanisms of anxiety disorders in PD and related treatment approaches.