Consistent with previous studies in Japan [which were conducted in 2005–2010 (12) and 2008–2016] (13, 14), studies in other countries (9, 24, 25), and treatment guidelines (11, 26, 27), levodopa was the most commonly prescribed anti-PD drug in this study, with non-ergot DAs, MAO-B inhibitors, and zonisamide added or subtracted to levodopa monotherapy as needed. This evidence concerns the gene MAOB and Parkinson disease.