The prevalence of depression in isolated/idiopathic rapid eye movement sleep behavior disorder: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to investigate depression prevalence and depression-related symptoms among patients with isolated/idiopathic rapid eye movement sleep behavior disorder (iRBD). We systematically searched online databases (PubMed and Scopus), performed meta-analyses of psychiatric symptoms prevalence using a random-effects model, and calculated 95% prediction intervals (PIs) and I values to evaluate the degree of heterogeneity. We conducted a meta-regression analysis to assess the relationship between psychiatric symptom severity, age at diagnosis, and disease duration from onset of iRBD. We analyzed 31 studies which included 3,576 patients (2,871 men, 80.3%; mean age, 66.6 ± 8.6 years). The pooled depression prevalence was 28.8% (95% CI 23.1-35.2, 95% PI 8.1-65.1, and I = 83.9%). We found a significantly negative correlation between depression-scale scores and disease duration in iRBD (p = 0.012, β = -0.36, R analog = 0.33). Pooled prevalence of apathy and anxiety was 38.4% (95% CI 27.7-50.4, 95% PI 0.02-99.9, and I = 57.8%) and 21.3% (95% CI 15.5-28.5, 95% PI 4.2-62.6, and I = 47.1%), respectively. Few articles on alexithymia were available for meta-analysis. This study confirmed high prevalence of depression, apathy, and anxiety in patients with iRBD.