Prevalence of anxiety in Parkinson's disease: a systematic review and meta-analysis.

Prevalence rates of anxiety disorders in Parkinson's disease (PD) vary widely, ranging from 6% up to 55%. The aim of this systematic review was to calculate the average point prevalence of anxiety disorders and clinically relevant anxiety symptoms in PD.Using PubMed, we carried out a systematic literature search for studies reporting Diagnostic and Statistical Manual-defined anxiety disorders or clinically relevant anxiety symptoms assessed by an anxiety rating scale.A total of 49 articles were included and assessed for quality, and 45 articles fulfilled the quality criteria. The average point prevalence of anxiety disorders in PD was 31%, with nonepisodic anxiety being more prevalent than episodic anxiety. Generalized anxiety disorder was the most frequent in 14%, followed by social phobia (13.8%), anxiety not otherwise specified (13.3%), and specific phobia (13.0%). Panic disorder with or without phobia was present in 6.8% of PD patients. Of the patients, 31% fulfilled the criteria for current multiple anxiety disorders. Based on anxiety rating scale cutoff scores, clinically significant anxiety symptoms were present in a weighted average of 25.7%.This systematic review confirms that anxiety, although often unrecognized, is very common and highlights the need for efficient identification of anxiety in PD. © 2016 International Parkinson and Movement Disorder Society