Frequency of mood and anxiety fluctuations in Parkinson's disease patients with motor fluctuations: A systematic review

After 5 years of treatment with levodopa, approximately 40% to 50% of patients with Parkinson's disease (PD) develop motor complications such as dyskinesias or motor fluctuations. These are often accompanied by nonmotor fluctuations, such as fluctuations in mood symptoms. The aim of this systematic review is to assess the frequency of such mood fluctuations in PD patients with motor fluctuations and to explore the association between these mood fluctuations and motor fluctuations. We performed a systematic literature search in PubMed, Medline, and the Cochrane Library. This search yielded 10 studies, of which 9 were included after quality assessment. The frequency of anxiety fluctuations in PD patients with motor fluctuations ranged from 3.1% to 67.7% with a weighted mean of 35.4%. The frequency of fluctuations in depressive symptoms ranged from 2.1% to 71.4%, with a weighted mean of 34.9%. The frequency of fluctuations in symptoms of panic ranged from 3.1% to 54.5%, with a weighted mean of 37.1%. Symptoms of anxiety and depression are mostly present in the "off" state. We conclude that mood fluctuations occur frequently in PD patients with motor fluctuations. The methodology used to assess mood fluctuation varies widely and there is a lack of a generally accepted assessment procedure for fluctuating symptoms. Research would benefit from a more uniform approach to assessment of nonmotor fluctuations. © 2018 International Parkinson and Movement Disorder Society.