Shin C, et al. - In patients with Parkinson's disease (PD), researchers determined the short-term effectiveness and safety of clonazepam [considered to be first-line treatment for rapid eye movement sleep-related behavior disorder (RBD) in PD] for the treatment of probable RBD (pRBD) by conducting a four-week, randomized, double-blind, placebo-controlled trial. In patients with PD, clonazepam (0.5 mg/day at bedtime) compared to a placebo for RBD symptoms. From April 2015 to February 2016, patients aged 30 years or older who had a caregiver who could observe RBD symptoms were recruited. A total of 40 patients have been enrolled, 20 receiving clonazepam and 20 receiving a placebo. In patients with PD, both clonazepam and placebo tended to improve symptoms of pRBD. Due to limitations in the design of the study, no firm conclusion was drawn on the effectiveness of clonazepam. This investigation highlighted the importance of conducting future large-scale, randomized trials with better evaluation tools and polysomnography to provide evidence for clonazepam's benefit.