All the studies conducted research on subjects with PD and evaluated the presence or absence of sleep disorders in 1.181 subjects of which: 864 PD, 139 with PD without dementia, 96 healthy subjects, 301 PD with RBD, 128 PD without RBD, 78 subjects with RBD, 62 patients who took MAO-B with other drugs, and 52 took antagonists and levodopa. Here, MAOB is linked to dementia.